Answer:
31.5N
Explanation:
M = 63kg, v = 7.0m/s t = 14.0s F =?
Force = Mass * acceleration
but acceleration = change in velocity / time
a = dV/dt
F = (63 * 7.0) / 14
F = 31.5N
To calculate the force exerted by the jetpack, we use the astronaut's deceleration and mass. The deceleration is obtained from the change in velocity (from 7.0 m/s to 0 m/s in 14.0 s). Applying Newton's second law, the force equals to the mass (63 kg) multiplied by the deceleration (-0.5 m/s²), resulting in a force of 31.5 newtons in magnitude.
Explanation:The question is asking to calculate the force exerted by a jetpack that an astronaut uses to come to a stop relative to a spacecraft. First, we'll use the formula for acceleration (a) which is the change in velocity (Δv) divided by the change in time (Δt). In this case, the astronaut decelerates from 7.0 m/s to 0 m/s in 14.0 s, so the acceleration is -7.0 m/s divided by 14.0 s, which equals -0.5 m/s² (the negative sign indicates deceleration).
The next step is to apply Newton's second law of motion: F = ma, where F is the force, m is the mass, and a is the acceleration. Plugging in the values we have: F = 63 kg * (-0.5 m/s²) = -31.5 N. The negative sign indicates that the force is in the opposite direction of the initial velocity, i.e., to the left if the initial movement was to the right.
The magnitude of the force exerted by the jetpack is 31.5 newtons.
Calculate the amount of heat needed to melt 35.0 g of ice at 0 ºC.Express your answer in kilojoules
The amount of heat needed to melt 35 g of ice will be equal to 2,800 calories and in kilojoule is 11.7152 KJ.
What is heat?Heat is energy that is transmitted from one object to another when temperatures are varied. When two bodies of various temperatures are brought together, energy is exchanged, or heat flows, from the hotter body to the colder. The result of this transfer of energy is typically, but not always, a warming of the colder body and a reduction in the temperature of the hotter body.
By migrating from one physical state (or phase) to the other, such as melting from a solid to a liquid, sublimation from the solid to a vapor, boiling from a fluid to a vapor, or shifting through one solid form to the other, a substance can absorb heat while increasing in temperature.
The latent heat of ice = 80cal/g.
So, the amount of heat required
= 35× 80cal
= 2,800 cal. Or,
2800 × 0.004184 = 11.7152 KJ.
Therefore, the amount of heat needed to melt the ice is 11.7152 KJ.
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A bee flies forward at 4.9m/s for 48s , lands on a flower and stays there for 28s , then flies back along its previous route at 5.1m/s for 38s . What is the total displacement of the bee? Round your answer to the nearest thousandth, if necessary.
"Displacement" is the distance and direction between the start-point and the end-point, regardless of the route taken on the way.
From this definition, it's easy to see that the bee's displacement at the end of the adventure is zero.
The bee's distance and average speed could also be calculated using the given information, but are not requested.
The total displacement of the bee is calculated by subtracting the return displacement from the forward displacement, resulting in a total displacement of 41.4 meters in the direction of the initial forward flight.
To calculate the total displacement of the bee, we need to consider the distance traveled in each direction and then sum these distances, taking into account the direction of travel. Initially, the bee flies forward at 4.9m/s for 48s, and then it returns along its previous route at 5.1m/s for 38s.
First, we calculate the forward displacement:
4.9m/s * 48s = 235.2m
Then, the return displacement:
5.1m/s * 38s = 193.8m
Since displacement is a vector quantity, we must consider the direction. The total displacement would be the forward displacement minus the return displacement because the bee returns along its previous route.
Total displacement = 235.2m - 193.8m = 41.4m
Therefore, the total displacement of the bee, rounded to the nearest thousandth if necessary, is 41.4m in the direction of the initial forward flight.
28. Sound can be heard around a corner because of
Answer:
Diffraction of sound wavelengths.
Explanation:
[tex]Diffraction[/tex]-A wave is able to bend around a corner due to the effects of diffraction. sound aves are capable of bending around corners in the same magnitude as it's wavelength making it possible to hear sounds around corners.
v=vi+at^2 dimensional correct
Answer:
Yes, dimensionally the equation is correct.
Explanation:
This equation is the kinematic equation for uniformly accelerated motion, then we study the units of each member to conclude whether it is dimensionally correct.
vi = initial velocity [m/s]
a = acceleration [m/s^2]
t = time [s]
v = final velocity
therefore we have:
[m/s] + [m/s^2]*[t^2], the second term now is m/s
[m/s] + [m/s] = [m/s]
So the analysis is correct.
What is the potential energy of a 2kg object placed 6m above
the surface of the Earth?
Answer:117.6joules
Explanation:
Mass(m)=2kg
Height(h)=6m
Acceleration due to gravity(g)=9.8m/s^2
Potential energy(PE)=?
PE=m x g x h
PE=2 x 9.8 x 6
PE=117.6joules
During a tornado in 2008 the peachtree plaza Westin hotel in downtown Atlanta suffered damage. Suppose a piece of glass dropped near the top of the hotel falls 215 meters. What will the velocity of the piece of glass be when it strikes the ground?
Answer: 64.91 m/s
Explanation:
This situation is related to free fall, since we are told the piece of glass "dropped".
Now, since this can be considered a one-dimension problem, we can use the following equation:
[tex]V^{2}=V_{o}^{2}+2gd[/tex]
Where:
[tex]V[/tex] is the final velocity of the glass
[tex]V_{o}=0 m/s[/tex] is the initial velocity of the glass
[tex]g=9.8 m/s^{2}[/tex] is the acceleration due gravity
[tex]d=215 m[/tex] is the distance from where the glass fell
Isolating [tex]V[/tex]:
[tex]V=\sqrt{V_{o}^{2}+2gd}[/tex]
[tex]V=\sqrt{2(9.8 m/s^{2})(215 m)}[/tex]
[tex]V=64.91 m/s[/tex] This is the final velocity of the glass
How much force is needed to accelerate a 34 kg skier at 4 m/s2?
Answer:
Net force needed to accelerate the skier is 136 N
Explanation:
As per Newton's 2nd law we know that net force on the system is product of mass and its acceleration
here we know that
m = 34 kg
[tex]a = 4 m/s^2[/tex]
so we have
F = ma
[tex]F = 34 \times 4[/tex]
[tex]F = 136 N[/tex]
What is the wave length of a water wave.
Answer:
It depends on the frequency and amplitude of the wave itself. Or a more simple way would be if you have a diagram or a picture take a ruler and measure in cm to get the wavelength. Hope this helped!
Explanation:
2 Points
Which of the following means the same thing as 'a guess you make about
what the results of your experiment will be?
O
A. Investigation
O
B. Question
O
C. Prediction
O
D. Summary
SUBMIT
PREVIOUS
Answer:
C. Prediction
Explanation:
A guess made about the results of an experiment is a called a prediction.
Prediction is the probability that an event will occur or not.
It is used widely in formulation of hypothesis. A hypothesis is simple scientific guess, therefore, we can say, it is a scientific prediction. When experiment is conducted and it fits the predictive model, we can conclude that our prediction is correct. Prediction is common process in scientific method.
Your lab group has been given a mixture of sand and water. The task at hand is to separate the sand from the water, producing a container of sand and a second container of water. Maria suggests using the procedure called crystallization but several other group members think that filtration would be the best way to separate the two. Provide support for the second separation method, filtration. All BUT ONE point is valid.
A) Sand is an insoluble solid that does not dissolve in water.
B) The two parts of the mixture, sand and water, have different boiling points.
C) Sand particles are large enough to be stopped by a piece of filter paper, separating the sand from the water.
D) Although crystallization would separate the sand from the water, it would not provide a method to collect the water.
Answer:
The answer is B
Explanation:
I just took it on USATESTPREP
Filtration is the best method to separate sand from water because sand is insoluble, filter paper can trap sand particles, and crystallization does not collect water.
Explanation:The best method to separate sand from water in this scenario is Filtration. Filtration is a process that uses a porous material, such as filter paper, to separate solid particles from a liquid. This method is effective because:
Sand is an insoluble solid that does not dissolve in water. Unlike soluble substances, sand particles do not dissolve in water and can be physically separated. Sand particles are large enough to be stopped by a piece of filter paper, separating the sand from the water. The filter paper acts as a barrier, allowing only the liquid (water) to pass through and trapping the solid particles (sand). Although crystallization would separate the sand from the water, it would not provide a method to collect the water. Crystallization is a process where a dissolved solute is separated from a solvent by cooling or evaporation. However, it is not an efficient method for collecting the water component of the mixture. Learn more about Separation Methods here:
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An FM radio station broadcasts at 9.23 × 107 Hz. Given that the radio waves travel at 3.00 × 108 m/s, what is the wavelength of these waves?
Answer:
3.2m
Explanation:
Given parameters:
Frequency of the FM radio = 9.23 x 10⁷Hz
Velocity of the waves = 3 x 10⁸m/s
Unknown:
Wavelength of the wave = ?
Solution:
To solve for the wavelength of the wave, we need the velocity equation;
Velocity = frequency x wavelength.
Radio waves are all electromagnetic radiations produced by both electrical and magnetic fields perpendicularly oriented to one another.
Since the unknown is wavelength, we solve for it:
3 x 10⁸ = 9.23 x 10⁷ x wavelength
wavelength = [tex]\frac{ 3 x 10^{8} }{9.23 x 10^{7} }[/tex]
wavelength = 3.2m
Answer:
3.25
Explanation:
on edge :)
9) Which is a difference between plant and animal cells?
Answer:Plant Cells have big Vacouls whereas Animal cell have small Vacouls. Plant Cell have cell wall and cell membranes but animal cell has got cell membranes only. Plants cell has Chloroplast and whereas in animal cell it's absent. Plastids absent in animal cell and present in plant cell.
Explanation:
How does seismic waves cause earthquakes?
Answer:
Seismic waves cause Earthquakes by shaking the ground aggressively and dangerously. These waves are usually calculated on a seismograph to calculate how hard the earthquake hit that area. A transform Boundary creates the tension when the tectonic plates gets stuck. It stays stuck for a long period of time. Then, at one point, the tectonic plates become unstuck which releases the tension into waves which are called seismic waves. Hope I answered you question.
Sound waves don't cause earthquakes.
When parts of the Earth shake and quake and rub against each other, THAT's an earthquake.
THEN, whenever anything is shaking, THAT makes sound waves.
A crane lifts an l-bean to a height of 30 meters giving it a potential energy of 108,486). What is the mass of the I-beam?
369 kg
Explanation:
Step 1:
We know that the expression for potential energy is
PE = mgh
where, m =Mass
g = Acceleration due to gravity
h Height
Step 2:
Here m = ?
PE = 108486
h = 30 m
g = 9.8 ms⁻²
108486 = [tex]30 * 9.86 * m[/tex]
[tex]m= 108486 / (9.8*30) = 369 kg[/tex]
A hypothetical situation of being stranded on a deserted island without water is often posed to students. A model of a process used to separate salt water into its components is shown here. Justify the use of the flame in the model depicting the separation of the mixture.
A) The flame will sterilize the water, so that water from the ocean will be consumable. This is known as sanitation.
B) The flame will allow the pure water and salt water to separate into different layers. This is known as density separation.
C) The flame will burn the salt component of the mixture, leaving only the pure water behind for drinking. This is known as combustion.
D) The flame will allow the water to evaporate and be collected in its pure form, leaving the salt component behind. This is known as distillation.
Answer:
The correct answer is D!
Explanation:
I got it wrong when I put C.
The flame will allow the water to evaporate and be collected in its pure form, leaving the salt component behind. This is known as distillation. Hence, option (D) is correct.
What is distillation?A separation process called distillation is used to remove the solvent-containing liquid from a combination and retain the liquid portion. Boiling the solution and then cooling it causes the vapor to condense back into a liquid during distillation.
We can distil salt water to get pure water that is safe to drink. To accomplish this, take the following actions:
In a flask, the salt solution is put and heated until it boils.While the salt remains in the flask, the water gasifies.The condenser receives the steam. A layer of cold water surrounds the condenser, which is a tube. As a result, the steam cools and transforms back into a liquid.Pure water makes up the distillate.Learn more about distillation here:
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A 7.0kg skydiver is descending with a constant velocity
Answer:
The air resistance on the skydiver is 68.6 N
Explanation:
When the skydiver is falling down, there are two forces acting on him:
- The force of gravity, of magnitude [tex]mg[/tex], in the downward direction (where m is the mass of the skydiver and g is the acceleration due to gravity)
- The air resistance, [tex]R[/tex], in the upward direction
So the net force on the skydiver is:
[tex]F=mg-R[/tex]
where
m = 7.0 kg is the mass
[tex]g=9.8 m/s^2[/tex]
According to Newton's second law of motion, the net force on a body is equal to the product between its mass and its acceleration (a):
[tex]F=ma[/tex]
In this problem, however, the skydiver is moving with constant velocity, so his acceleration is zero:
[tex]a=0[/tex]
Therefore the net force is zero:
[tex]F=0[/tex]
And so, we have:
[tex]mg-R=0[/tex]
And so we can find the magnitude of the air resistance, which is equal to the force of gravity:
[tex]R=mg=(7.0)(9.8)=68.6 N[/tex]
How does mass affect the force of gravity between 2 objects?
Answer:
Force due to gravity increases on increasing the masses and decreases on decreasing the masses.
Explanation:
The force due to gravity (F) acting between any two given bodies can be expressed as,
[tex]F = G\frac{m_{1} m_{2}}{r^{2}}[/tex]
Here,
G = gravitational constant
[tex]m_{1}[/tex] = mass of the first body
[tex]m_{2}[/tex] = mass of the second body
[tex]r =[/tex] separation between the bodies
It is clear from the above expression that the force due to gravity acting between the two bodies is directly proportional to the product of the masses of the bodies.
1. What is the atomic number of an atom? Why is this number important? |
Answer:
The atomic number is the number of protons in an atom's nucleus.
The atomic number is important, because it determines which element an atom is.
Answer:
Explanation:
It is the number of protons in the nucleus which determines all the characteristics of the atom and its place on the periodic table
An object falls 210 m in 6.3 s. What was it's initial velocity? Express your answer with the correct number of significant digits.
Answer:
[tex]u = 2.5 \ m/s[/tex]
Explanation:
Given data:
Height, [tex]h = 210 \ m[/tex]
Time, [tex]t = 6.3 \ s[/tex]
Let the initial velocity of the object be u.
From the kinematic equation,
[tex]h = ut + \frac{1}{2}gt^{2}[/tex]
[tex]210 = u \times 6.3 + 0.5 \times 9.80 \times (6.3)^{2}[/tex]
[tex]\Rightarrow \ u = 2.46 \ m/s[/tex]
[tex]u = 2.5 \ m/s[/tex] (rounding to tenth place)
Final answer:
The object's initial velocity was calculated to be 62 m/s after falling 210 m in 6.3 s.
Explanation:
The initial velocity of the object can be calculated using the formula:
v = u + gt
where:
v is the final velocity (0 m/s as the object stops), u is the initial velocity, g is the acceleration due to gravity (-9.8 m/s²), and t is the time taken (6.3 s).
Plugging in the values:
0 = u - 9.8*6.3
u = 9.8*6.3
u = 61.74 m/s
Rounded to the correct significant digits:
u = 62 m/s
NEED !!!!!!
A paper clip is an example of a_________
A. bar magnet
B. Insulator
C.permanent magnet
D.magnetic material
A paper clip is an example of a magnetic material that can be temporarily magnetized by rubbing it with a permanent magnet, causing it to attract other ferromagnetic objects like another paper clip.
Explanation:A paper clip is an example of a magnetic material. Magnetic materials are materials that can be magnetized and are attracted to magnets. Some commonly known magnetic materials include iron, nickel, and cobalt. In this case, the paper clip can be attracted to a magnet because it contains iron, which is a magnetic material.
A paper clip is an example of a magnetic material. When you rub a permanent magnet along a paper clip, the paper clip becomes temporarily magnetized due to the alignment of the magnetic domains within the material. This temporary magnetization allows the paper clip to exhibit magnetic properties, such as attracting other ferromagnetic objects. If you place this magnetized paper clip near another paper clip, the untouched paper clip will experience an attractive force, as seen in classroom experiments. Ferromagnetic materials like iron, which paper clips are commonly made of, can be magnetized and therefore are strongly attracted to magnets, unlike insulators or temporary electromagnets that require a current to become magnetized.
David rides his bike with a constant speed of 12 miles per hour. How long will it take to travel a distance of 18 miles?
Answer:
1.50 h
Explanation:
For an object moving in uniform motion (= moving at cosntant velocity), the relationship between speed, distance and time is given by:
[tex]v=\frac{d}{t}[/tex]
where:
v is the speed of the object
d is the distance covered
t is the time taken to cover the distance
For this problem, we have:
d = 18 miles is the distance covered by David
[tex]v=12 mi/h[/tex] is David's speed
Therefore by re-arranging the equation, we can find the time taken by David to cover that distance:
[tex]t=\frac{d}{v}=\frac{18}{12}=1.5 h[/tex]
when an object moves down and does not stop which force is acting more strongly on the object, friction or gravity? explain
Gravity acts more strongly on the object.
Explanation:
When an object is dropped from a height, it reaches the ground despite friction acting on it because the force of gravity acting on it is stronger than the air resistance and friction. Air resistance and friction acts upward and prevents the ball from falling. However, it is negligible. The gravity acting on the object is so strong that it pulls the object towards earth with a constant acceleration called as acceleration due to gravity which has a constant value of 9.8m/s².
Showing your work clearly, what is the angle between two vectors A and B if
A=3.0i - 4.0j
B=-2.0i+3.0k
Answer:
[tex]\large\boxed{\large\boxed{70.6\º}}[/tex]
Explanation:
1. Calculate the scalar product using the coordinates
[tex]A\cdot B=(3.0\hat i-4.0\hat j+0\hat k)\cdot (-2.0\hat i+0\hat j+3.0\hat k)\\\\A\cdot B=(3)(-2)+(-4)(0)+(0)(3)=-6[/tex]
2. Write the scalar product using the cosine of the angle
[tex]A\cdot B=|A|\cdot |B|\cdot cos\theta[/tex]
[tex]|A|=\sqrt{(3.0)^2+(-4.0)^2}=\sqrt{9.0+16.}=5.0[/tex]
[tex]|B|=\sqrt{(-2.0)^2+(3.0)^2}=\sqrt{4.0+9.0}=\sqrt{13.0}[/tex]
3. Equal the two scalar products and solve for cos(θ)
[tex]-6.0=(5.0)(\sqrt{13.0})cos\theta\\\\cos\theta=0.3328\\\\\theta = arccos(0.3328)=70.6\º[/tex]
How long can a flashlight run for if it draws 0.11 amps and its battery contains 10 coulombs of charge?
Answer:
Battery will run for t = 90 s
Explanation:
As we know that rate of flow of charge is known as electric current
So we will have
[tex]i = \frac{Q}{t}[/tex]
[tex]i = 0.11 A[/tex]
[tex]Q = 10 C[/tex]
now we have
[tex]t = \frac{Q}{i}[/tex]
[tex]t = \frac{10}{0.11}[/tex]
[tex]t = 90 s[/tex]
Final answer:
A flashlight that draws 0.11 amps can run for about 90.91 seconds on a battery with 10 coulombs of charge.
Explanation:
To calculate how long a flashlight can run with a given amount of charge, we use the relationship between current, charge, and time. Current (I) is the rate of flow of charge over time (Q), represented by the formula I = Q/t, where t is the time in seconds. Given the flashlight draws 0.11 amps (A) and the battery has a charge of 10 coulombs (C), we can rearrange the formula to solve for time: t = Q/I. Therefore, t = 10 C / 0.11 A, which equals approximately 90.91 seconds. Therefore, the flashlight can run for about 90.91 seconds on a battery with 10 coulombs of charge.
Which two factors does the power of a machine depend on?
OA. work and distance
OB. force and distance
OC. work and time
OD. time and distance
The power of a machine depend on two factors are work and time.
Option C
Explanation:
In science, power defined as the amount of work done in a unit time. i.e. delivering work in a rate of time or energy supply, expressed in input of work or transmitted energy divided by the time interval (t) or W/t.
Example: Some work can be done in the long run with a low-power engine or in a short time with a motor with high performance. The equation for power can be given as
[tex]Power\ (in\ watts) =\frac{\text { work (joules) }}{\text { time (seconds) }}[/tex]
[tex]P=\frac{W}{t}[/tex]
A weightlifter lifts a barbell above her head. Is there work done on the barbell?
Answer:
Yes
Explanation:
The work done on a body relies upon the force, displacement, and the angle made between the force and the displacement.
Here, the force acting on the barbell is vertically downwards while the vertical displacement is in the upward direction. The angle made between the force (weight) and the displacement is [tex]180^{\circ}.[/tex] Thus, a work will be done on the barbell by its weight.
The work done on a body relies upon the force, displacement, and the angle made between the force and the displacement.
What is force?
A force is a push or pull upon an object resulting from the object's interaction with another object. Whenever there is body with some mass than there is force.
Work in physics is the energy that is transferred to or from an item when a force is applied along a displacement. In its simplest form, it equals the product of the force's magnitude and the distance traveled for a constant force directed in the direction of motion.
Here, the force acting on the barbell is vertically downwards while the vertical displacement is in the upward direction. The angle made between the force (weight) and the displacement.
Thus, a work will be done on the barbell by its weight.
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As the pendulum swings from point A to Point E, what will happen to the values for potential and kinetic energy?
Kinetic energy will increase from 0 J to 12 J and the potential energy will decrease from 12 J to 0 J.
Kinetic energy will decrease from 12 J to 0 J and the potential energy will increase from 0 J to 12 J.
Kinetic energy will decrease from 0 J to 12 J and the potential energy will increase from 12 J to 0 J.
not enough information to determine
Answer:
Kinetic energy will increase from 0 J to 12 J and the potential energy will decrease from 12 J to 0 J.
Explanation:
-As the bob swings downwards it loses height. So its gravitational potential energy (GPE) decreases.
-The subsequent work done on the pendulum by the gravitational force increases its kinetic energy.
-At all points, by Law of Conservation of Mechanical Energy, during the swing the total ptential energy plus kinetic energy is constant.
Answer:
Explanation:
give that person brainlist
diagram shows the velocity time graph for a particle moving in 16 seconds.
Find
a)The maximum acceleration of the particle
b)The deceleration of the particle
c)The total distance travelled by the particle
d)The average velocity of the particle
Answer:
The detailed calculations are shown below;
Explanation:
a)The maximum acceleration of the particle:
It is seen that the maximum change in velocity is at the time between 8s to 10s.
Maximum acceleration: [tex]\frac{V}{t}[/tex]
= [tex]\frac{20}{2}[/tex]
= 10 m/[tex]s^{2}[/tex]
b) The deceleration of the particle
The velocity of particle is decreased after 10s so,
deceleration = - [tex]\frac{40}{6}[/tex]
= - 6.67 m/[tex]s^{2}[/tex]
c)The total distance traveled by the particle = Area under the curve
= [tex]\frac{1}{2}[/tex]* 4*20 + 4*20 + [tex]\frac{1}{2}[/tex]* 2*20+ 2*20+ [tex]\frac{1}{2}[/tex]* 40*16
= 290 m
d)The average velocity of the particle = [tex]\frac{Area under the curve}{Total time}[/tex]
= [tex]\frac{290}{16}[/tex]
= 18.12 m/s
the average speed of a car that travels a distance of 240 km is three hours
Answer:
80km/h
Explanation:
Average speed = distance/time
Given
Distance = 240km
Time = 3 hours
speed = 240km/3hrs
= 80km/h
is kinetic energy scalar quantity
Yes, Kinetic Energy is a scalar quantity because the direction is not needed. A scalar quantity is one dimensional measurement.
Explanation:
Kinetic Energy is a scalar quantity that means it has only a magnitude and no direction.Energy has a size but no direction; two objects can have the same kinetic energy but they travel in opposite directions.The formula of Kinetic Energy isK.E = [tex]\frac{1}{2} mv^{2}[/tex]Mass is a scalar quantity and velocity is a vector quantity.squaring velocity will make vector to scalar quantity.The kinetic energy is a scalar quantity as it requires only magnitude for description.
Explanation:
Scalar quantity refers to the quantity that has a single dimension. It is not dependent on the direction and has magnitude only, like Temperature and Mass.
Kinetic energy is possessed when the object is set in motion. Any object whether it is moving straight or spinning possess kinetic energy. It depends on two variables, namely, mass and velocity or speed of the object.
Kinetic Energy: K.E. = [tex]\frac{1}{2}[/tex] × m × v²
The metric unit to measure Kinetic energy is Joule (J).