Answer:
7.0 m/s
Explanation:
The question is on Free-Fall
In a free fall, an object falls freely without only gravity acting on it. Velocity at the top is zero m/s
Height of fall, h=1/2gt²
Velocity, v=gt where g is gravity acceleration=9.8m/s² and t is time taken fall the fall
Finding the t taken for the fall;
h=2.5m but we know h=1/2gt²⇒substitute values in this equation
2.5=1/2×g×t²
2.5=1/2×9.8×t²⇒2.5=4.9t²
make t subject of the equation;
t²=2.5/4.9
t=√2.5/4.9 =0.7143sec
Finding the velocity
v=gt
v=9.8×0.7143=7m/s
A car headed north at 15m/s experiences an acceleration of 2.5 m/s2 for 3 s. What is the final velocity of the car
Answer:
= 22.5 m/s
Explanation:
The acceleration of a moving body is calculated by the formula;
a = (v-u)/t
Where; a is the acceleration of the body
v is the final velocity of the body
u is the initial velocity of the body and
t is the time taken
In this case;
u = 15 m/s
a = 2.5 m/s²
t = 3 seconds
2.5 m/s² = ( v- 15 m/s)/3 seconds
2.5 × 3 = v - 15
7.5 = v - 15
v = 7.5 + 15
= 22.5 m/s
Please tell me the order the answers go. Best and most correct answer gets Brainliest.
See the attached picture:
What is another name for the surface of the sun?
Answer: Chromosphere hope this helps :)
In young’s experiment how must waves be vibrating to for interference to occur
A. Out of line
B. In line
C. In phase
D. Out of ohase
In phase for constructive interference and out of phase for destructive
As object moving east, and it’s velocity changes from 65 m/s to 2/5ms in 10 seconds. Which describes acceleration?
Answer:
-4.0 m/s^2
Explanation:
Acceleration is defined as the rate of change in velocity:
[tex]a=\frac{v-u}{t}[/tex]
where
v is the final velocity
u is the final velocity
t is the time elapsed
For the object in this problem,
u = 65 m/s
v = 25 m/s
t = 10 s
So the acceleration is
[tex]a=\frac{25 m/s-65 m/s}{10 s}=-4.0 m/s^2[/tex]
The negative sign tells that the acceleration is opposite (=west) to the velocity (which is towards east).
Answer:
A
Explanation:
I’m gay
A yo-yo is swung around the head of a person in a horizontal circle. What provides the
centripetal force on the yo-yo?
Answer:
There is a net force towards the center of the circle that causes the yo-yo to seek the center.
Circular Motion Qualities:
-Constant speed
-Accelerating
-Velocity is changing constantly.
Centripetal acceleration perpendicular to the motion causes the object to change direction
a_c=v^2/r
Tangential acceleration in the direction of the motion causes and increase or decrease in speed.
Tension in the string towards the center provides the centripetal force in a a yo-yo swinging around a person's head.
Centripetal force is the force that keeps an object moving in a circular path. In the case of a yo-yo swung around a person's head, the centripetal force is provided by the tension in the string acting towards the center of the circle. This force allows the yo-yo to maintain its circular motion.
Which property describes the amount of energy that flows past a given area per unit of time
Answer:The property that describes the amount of energy that flows past a given area per unit of time is called energy flux, denoted by S1. It can be calculated by dividing the energy by the area A and the time interval Δ t. The formula for energy flux is S = Energy passing area A in time Δ t A Δ t = u c = ϵ 0 c E 2 = 1 μ 0 E B1. In electromagnetism, current density is the amount of charge per unit time that flows through a unit area of a chosen cross section2.
Explanation:
What basic parts does a circuit need?
Answer:
Every electric circuit, regardless of where it is or how large or small it is, has four basic parts: an energy source (AC or DC), a conductor (wire), an electrical load (device), and at least one controller (switch).
Explanation:
Cell (battery)
Wires
Bulb or motor
Which statement does Einstein's theory promote about space and time?
O
O
O
O
Time, space, and the speed of light depend on reference frames.
Time and space depend on reference frames, but the speed of light does not.
The speeds of light and space depend on reference frames, but time does not.
The speeds of light and time depend on reference frames, but space does not.
Answer:
2nd statement would be the right answer
Answer: Time and space depend on reference frames, but the speed of light does not.
Explanation: According to Einstein Space and Time are directly related as the way we sense them, in his words space and time is like a fabric in which we cannot affect one without affecting the other as we interact with it, time can be stretched and squeezed depending on your inertial frame of reference (constant speed and mass). However light can travel thru the fabric of space and time and it does not get affected by any reference keeping always the same speed.
a 225 kg bumper is moving north at .98 m/s when it hits a 198 kg car moving north at .28 m/s. the 198 kg car is moving north at .71 m/s after the collision. what is the post collision velocity of the 225 kg car?
Answer:
= 60.16 cm/s or 0.6 m/s
Explanation:
Using the formula for collision;
M1U1 + M2U2 = M1V1 + M2V2
Therefore;
(225 kg)•(98 cm/s) + (198 kg)•(28 m/s) = (225 kg)•v + (198 kg)•(71 cm/s)
22050 kg•cm/s + 5544 kg•cm/s = (225 kg)•v + 14058 kg•cm/s
13536 kg•cm/s = (225 kg)•v
v = 60.16 cm/s
Therefore; the post collision velocity of the 225 kg car is 60.16 cm/s
Which best describes a material with a low index of refraction (near 1)?
A. It causes light to refract significantly.
B. The speed of light stays constant.
C. Is causes light to slow and refract very little.
D. Light is mostly reflected at a value near 1.
it causes light to slow and refract very little
Answer:
it causes light to slow and refract very little
Explanation:
its on my test
You use a pulley system to lift a fallen tree . You apply a force of 50 N and the pulley pulls on the tree with a force of 1300 N what is the mechanical advantage of the pulley ?
Mechanical Advantage = (output force) / (input force)
Mechanical Advantage = (1300 N) / (50 N)
Mechanical Advantage = 26
The mechanical advantage of pulley is that with less applied force we can get large amount of work.
To find the answer, we need to know about the pulley system.
What is a pulley system?A pulley system is a wheel on an axle or shaft which is designed to support the movement and change the direction of a taut cable or belt, or transfer the power between the shaft and cable or belt.
What is the basic idea of a pulley system work?In a pulley system, we get a huge amount of force from a less amount of applied force.
Thus, we can conclude that the mechanical advantage of pulley is that with less applied force we can get large amount of work.
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Explain how the sun's position in the sky affects the length of shadows
ps.multiple sentences, please
A shadow forms on the side of an object that faces away from the sun. The length of shadows changes as Earth rotates. In the morning, the sun is low in the eastern sky and shadows are long. As time passes in the morning, the sun seems to move higher in the sky.
The size of the object changes with change in the position of the light source.The length of the shadow of the object decreases as the sun position changes from down to top in the sky.
SunlightSunlight has the sun rays. This rays travel to the earth. When the sun rays reach to earth they hit the object comes in his way. If the sun rays hit the opaque body ( a body that absorb some light when light fall on it) the light can not pass through them and the shadow appears.
What is the affect pf sun's position on the length of shadows?The shape of a object determine the shape of the shadow made by him but the size of the object does not depends on the size of the object.
The size of the object changes with change in the position of the light source.The shadow appears in the opposite direction from where the sunlight falls on body.
At the outdoor, when there is sun in the sky, the size of the shadow is different at different sun position on the sky.
At the time of morning the sun is in the east direction low level at sky. At this position the sun rays passes through the objects vertically. It results in the long shadow of the object in the west direction.At the time of noon the sun is at top of the sky. The sun rays fall on a object vertically. The shadow made by the object is smaller or nothing as the opposite surface is grounded. Thus in the noon time the shadow length is smaller.At the time of evening the sun is again down in the sky. The sun rays falls vertically, Hence the shadows made by the object is longer and in the east direction.Hence the length of the shadow of the object decreases as the sun position changes from down to top in the sky.
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How does water affect metamorphic processes?
Answer:
When the temperature and pressure of a rock undergoing metamorphism changes. the composition of water allows materials to move more easily, the presence of fluids makes metamorphism more easy.he fluid changes also.
Explanation:
Answer:
It can have elevated concentrations of dissolved substances
Explanation:
Cause I happened to know
What is pitch related to in terms of sound? Does it affect the speed? If so, how?
Answer:
Pitch is the listener's perception of the frequency of sound, but it does affect the speed.
Explanation:
Depending on the frequency at which the sound waves that produce them vibrate, sounds have a higher or lower pitch.
What is the pitch of the sound?A low frequency, such as 55 Hz, is heard as a low pitch and a high frequency, such as 880 hertz [Hz; cycles per second], as a high pitch.
In frequency, hertz units are used. The pitch of a sound wave increases with the speed of oscillation.
Pitch and sound frequency are connected. The frequency increases as the pitch rise. The length of the vibrating item affects the frequency and pitch of the vibration.
For instance, a shorter string vibrates more quickly than a longer string, producing a greater frequency and pitch.
Therefore, the pitch is related to in terms of sound The higher the pitch of the sound, the higher the frequency, and vice versa, hence they are directly correlated.
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Application of a biot-savart law
can be used to determines the expression for magnetic field strength of a current element
The Biot-Savart law is important for calculating magnetic fields from current loops but can be complex and time-consuming. It requires the use of cross-products and integration along the current-carrying wire. When symmetry exists, Ampère's law might offer a simpler solution.
Explanation:One advantage of the Biot-Savart law is its ability to calculate the magnetic field produced by any current loop configuration, offering versatility in physics problems. A disadvantage is that it can be complex and time-consuming, particularly when dealing with intricate geometries where symmetry is lacking. When approaching a problem, if there is symmetry, one may consider Ampère's law as an alternative for simplifying calculations especially when a clear path of integration is present.
To apply the Biot-Savart law, it is necessary to define the current element dI and unit vector r, calculate their cross-product, and integrate this across the length of the current-carrying wire. This allows determination of the magnetic field's magnitude and direction. In specific setups, such as calculating the magnetic field of an infinite wire, the desired precision dictates certain assumptions like treating finite segments as effectively infinite when they align closely with the wire's length.
Overall, the Biot-Savart law provides a powerful tool for understanding how current-carrying wires influence the magnetic fields in their vicinity, which is a foundational concept in electromagnetism.
Which formula is used to calculate the mass of an object if the force and acceleration are known?
Answer: Multiply Both Volume And Density
Explanation: Multiply the volume and density together. Multiply your two numbers together, and you'll know the mass of your object.Keep track of the units as you do this, and you'll see that you end up with units of mass (kilograms or grams).
For this case we have by definition, Newton's second law of motion states that the force is directly proportional to the mass and to the acceleration of a body. That is to say:
[tex]F = m * a[/tex]
Where:
F: It's the strength
m: It's the mass
a: It's the acceleration
ANswer:
[tex]F = m * a[/tex]
A sphere is charged with electrons to
−7 × 10−6 C.
How many electrons make up this charge?
The elemental charge is 1.6 × 10−19 C.
Answer:
[tex]4.38\cdot 10^{13}[/tex] electrons
Explanation:
The net charge on the sphere is equal to:
[tex]Q=-7\cdot 10^{-6}C[/tex]
This charge is made up of N electrons. Each electron carries a charge of
[tex]q=-1.6\cdot 10^{-19}C[/tex]
So the total charge is just the number of electrons times the charge of each electron:
[tex]Q=Nq[/tex]
And solving the equation for N, we find the number of electrons:
[tex]N=\frac{Q}{q}=\frac{-7\cdot 10^{-6}C}{-1.6\cdot 10^{-19} C}=4.38\cdot 10^{13}[/tex]
A student has an 80 g sample of a radioactive material that has a half-life of 20 seconds. How much material will he have left after one minute?
a) 40 g
b) 1.33 g
c) 5 g
d) 10 g
Answer:
= 10 g
Explanation:
Half life is the time taken by a radioactive substance to decay by half of the original mass or initial amount.
Therefore, to get the new mass after decay;
New mass = Original mass × (1/2)^n ; where n is the number of half lives.
n = 60 seconds/20 seconds
= 3
Therefore;
New mass = 80 g × (1/2)^3
= 80 g × 1/8
= 10 g
The angle of reflection is the angle the ____ to the reflecting surface.
Reflected rays make with a perpendicular line
Instant raise makes with a perpendicular line
Instant ray makes with a parallel line
Reflected ray mix with a parallel line
Answer:
The angle of reflection is the angle the reflected rays make with a perpendicular line to the reflecting surface.
Explanation:
Reflection It is the change of direction suffered by a luminous ray when hitting the surface of an object. The angle of reflection is that which is formed by the reflected ray and the normal vector to the study surface
Answer:
Reflected rays make with a perpendicular line
Which part of an atom has most of its mass? A. electrons B. neutrons C. nucleus D. protons
The nucleus has most of the atomic mass in an atom. The nucleus is made up of protons and neutrons.
The nucleus of an atom is located at its center and contains most of its mass. The correct answer is C.
It is composed of protons and neutrons, which are collectively known as nucleons. Protons have a positive charge, while neutrons have no charge. Electrons, on the other hand, are negatively charged particles that orbit the nucleus in energy levels or shells.
Although electrons are much lighter than protons and neutrons, they occupy a larger volume around the nucleus due to their lower mass. The mass of an electron is approximately 1/1836th the mass of a proton or neutron.
Therefore, when considering the total mass of an atom, the mass of the electrons is relatively insignificant compared to the mass of the nucleus, which is primarily composed of protons and neutrons. The correct answer is C.
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Plants make energy. Some of it they use to preform the necessary functions of living. What do they do with the excess energy?
Answer:
They can use it for when they are dormant in the winter or to grow more sources for storing and creating energy, or they store the energy (this energy would be considered stored energy).
Dimension formula of under root LC
The square root of LC has the dimension of time. Its reciprocal is frequency.
The dimension of under root LC is calculated by taking square root of the multiplication of the dimensions of L (Inductance) and C (Capacitance). Using the dimensions of L as [M][L][T]-2 [I]-2 and C as [M]-1 [L]-2 [T]4 [I]2, the dimension of under root LC is [M]-1/2 [L]-1 [T]2 [I].
Explanation:The question asks for the dimension of under root LC where L is Inductance and C is Capacitance. Both of these are primary physical quantities where the dimension of L is [M][L][T]-2 [I]-2 and the dimension of C is [M]-1 [L]-2 [T]4 [I]2. To find the dimension for under root LC, we can square root the multiplication of the dimensions of L and C, which means that the dimension of under root LC is [M]-1/2 [L]-1 [T]2 [I].
Here, M stands for mass, L for length, T for Time, and I for Current.
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a 300-kg crate is placed on a adjustable incline plane. as one end of the incline is raised, the crate begins to move downward. if the crate slides down the plane with the acceleration of .70 m/s2 , when the incline is 25degrees, what is the coefficient of kinetic friction between ramp and crate?
Final answer:
To find the coefficient of kinetic friction, use the formula μk = a - sinθ / cosθ where a is acceleration and θ is the angle of the incline. By substituting the given values (a = 0.70 m/s², θ = 25°), the coefficient of kinetic friction is approximately 0.285.
Explanation:
The coefficient of kinetic friction can be calculated using the formula:
μk = a - sinθ / cosθ, where a = acceleration and θ = angle of incline.
Plugging in the values given (a = 0.70 m/s², θ = 25°), we get μk ≈ 0.285.
Your backpack has a mass of 8 kg. You drop it from a height of 1.3m. How much work is done by gravity as the backpack falls?
A. -102 J
B. -10.4 J
C. 102 J
D. 10.4 J
Answer:
The answer is C.
Explanation:
I guessed and it was right
Answer:
Work done by the gravity, W = 102 J
Explanation:
It is given that,
Mass of the backpack, m = 8 kg
It is dropped from the height of, h = 1.3 m
We have to find the work done by the gravity as the back pack fall. Work done by the gravity is given by the product of force and distance covered by an object. Mathematically, it is given by :
W = F × d
∵ F = m g
⇒ W = mg h
[tex]W=8\ kg\times 9.8\ m/s^2\times 1.3\ m[/tex]
W = 101.92 Joules
or
W = 102 Joules
So, the work done by the gravity is 102 J. Hence, this is the required solution.
an object at rest requires a force of 15 newtons to set it into motion. The force is greater than which force?
Answer:
Friction
Explanation:
Friction is a force that opposes the movement of an object's relative motion. Friction always goes against the attempted movement of the object when they are in contact. In other words, it is a force that prevents objects from sliding past each other.
The answer is friction.
I took the test and got it right.
can someone pls answer number 8 for me pls
Answer:
1.33 m
Explanation:
Tom weighs 600 N and is 2 meters from the pivot. So his moment is:
τ = Fr
τ = (600 N) (2 m)
τ = 1200 Nm
To balance the see-saw, Jeremy must create an equal and opposite moment.
τ = Fr
1200 Nm = (900 N) r
r = 1.33 m
So Jeremy must sit 1.33 m from the pivot on the other side.
In both the U.S. House of Representatives and U.S. Senate, which of the selections below is elected by the party with the most members of that chamber?
Select one:
A. Party Conference Committee Chair
B. Majority Leader
C. Minority Whip
D. Majority Whip
Answer In Letter form please
I believe the answer is B
Answer:
B
Explanation:
Because its just b trust me
which best describes how the sun rotates?
Answer:
The sun rotates more slowly at its poles.
Answer:
The sun rotates more slowly at its poles.
A 2.5-kg rock is dropped
Answer:
Okay it dropped now what..........................................
Explanation:
Is the rock okay I’m concerned