Answer:
=9.72 m/s
Explanation:
From the Newton's laws of motion;
x=2(v²cos∅sin∅)/g
Using geometry we see that 2 cos∅sin∅ = sin 2∅
Therefore, x= (v²sin 2∅)g, where v is the take off speed x the range and ∅ the launch angle.
Making v the subject of the formula we obtain the following equation.
v=√{xg /(sin 2∅)}
x=7.80
∅=27.0
v=√{7.8×9.8/sin(27×2)}
v=√94.485
v=9.72 m/s
To find the takeoff speed of an athlete performing a long jump, we can use the principles of projectile motion.
Explanation:To calculate the takeoff speed of an athlete performing a long jump, we can use the principles of projectile motion. Since the jump is treated as a projectile, we can break down the motion into horizontal and vertical components.
First, we need to find the vertical component of the takeoff speed. We know that the jumper leaves the ground at a 27.0 degree angle and lands 7.80m away. The vertical displacement can be calculated using the equation:
Δy = v0y * t - (1/2) * g * t^2
The horizontal component of the takeoff speed can be found using the equation:
Δx = v0x * t
By combining these two equations and solving for the takeoff speed, we can determine the answer.
u will get POINTS......
answer it fast... someone...
brainliest will be awarded for sure....
→calculate the pressure exerted by a body having a mass of 30kg over an area of contact 400cm2.
also explain it clearly... for every step there should be explanation...
Explanation:
mass of the body=30kg
area on which it is exerting pressure=400 cm2 to m2
=4m2
pressure it exerts=?
the formula for finding pressur in physics is F/A where the mass of the body is the force implied while area is taken as area
therefore:pressure=F/A
=30/4
=7.5 kgm/s2
=
Answer:
7500 N/m²
Explanation:
The formula for finding pressure = force/area
force = 30 kg we convert this to newtons.this is because pressure is in N/m²
30 x 10 = 300N
Area = 400cm² we convert to m² = 400/10000 = 0.04
pressure = force/ area
pressure = 300/0.04 = 7500 N/m²
If you need any more explanation pls do mention in the comment section so that i can help more.
Hope this helps and if it does mark as branliest answer thx
Entropy can only be decreased in a system if
Final answer:
Entropy can only be decreased in a system if energy transfer occurs. When energy is transferred into a system, it can decrease the entropy of that system.
Explanation:
Entropy can only be decreased in a system if energy transfer occurs. When energy is transferred into a system, it can decrease the entropy of that system. For example, if you gather marbles scattered around a room and put them into a cup, you are decreasing the entropy of that system through your work. Similarly, energy from the Sun can decrease the entropy of local systems on Earth. However, it is important to note that the overall entropy of the rest of the universe increases, to satisfy the second law of thermodynamics.
the coefficient of kinetic friction between a couch and the floor is 0.81. if the couch has a mass of 71 kg and you push it with a force of 650 n, what is the net force on the couch as it slides?
a: 696 n
b:86 n
c: 46 n
d:331 n
Answer:
B: 86 N
Explanation:
There are four forces acting on the couch. Weight pulling down, normal force pushing up, your applied force to the right, and friction opposing you to the left.
In the y-direction:
∑F = ma
N - W = 0
N = W = mg
In the x-direction:
Fnet = P - Fᵣ
Fnet = P - Nμ
Fnet = P - mgμ
Given P = 650 N, m = 71 kg, g = 9.8 m/s², and μ = 0.81:
Fnet = 650 - (71)(9.81)(0.81)
Fnet = 86 N
The voltage in a lightbulb is given by the equation V= IR. In this equation, Vis
the voltage, lis the current, and Ris the resistance. What is the current in a
lightbulb with a voltage of 35.0 V and a resistance of 175 n?
O A. 6125 A
O B. 1.40 A
O C. 0.200 A
O D. 5.00 a
V=IR
35=I(175)
*Divide both sides by 175*
0.2=I
C. 0.200 A
Hope this helps!!
The current in a lightbulb with a voltage of 35.0 V and a resistance of 175 ohm is 0.2 A.
Find the current in a lightbulb?Given:
The voltage in a lightbulb is given by the equation V=IR V is the voltage, I is current, and R is the resistance.The voltage of the lightbulb is given as 35.0 V.The resistance of the lightbulb is given as 175 Ohm.As the equation is given,
V= IR
where I is current, R is resistance and V is the voltage.
Now, I = V/R
As the value of Voltage and resistance of the lightbulb is given, we will put in the above equation, we get;
I = 35.0/ 175 A
I = 0.2 A.
Hence, the current of the lightbulb is 0.2 A.
Therefore, Option C is the correct answer.
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Which of the following is one way that technology can improve procut
?
Answer:
Answer: C. Machines replace workers and eliminate human effort from the production process.
This is sad but true. By replacing the human workers, product cost and productivity increases as the machines now a days can perform tasks both faster and more accurately than humans. The productivity will rise also because of the lessening of human error when it comes to production lines.
Explanation:
Please mark brainliest and have a great day!
The correct option is: C. Machines replace workers and eliminate human effort from the production process.
Option C suggests that technology can improve productivity by replacing human effort with machines, specifically through automation. This process can lead to increased efficiency, reduced production time, and cost-effectiveness. Machines can handle repetitive tasks at a faster rate and with precision, potentially enhancing overall output. However, it's important to note that this can also result in job displacement for certain roles. While automation can streamline processes and reduce manual labor, its implementation requires careful consideration of its societal and economic implications. Therefore, the effectiveness of technology in improving productivity depends on how it is integrated and managed within the broader context of the workforce and industry.
Complete Question:
Which of the following is one way that technology can improve productivity?
A. Powerful machines are less dangerous to industrial workers.
B. Better methods of production allow workers to earn higher wages.
C. Machines replace workers and eliminate human effort from the production process.
D. The assembly line enables more workers to participate in the production process.
26. A 40 kg boy jumps from a height of 4m onto a plate-form mounted on springs. As the
spring compress, the plate-form is pushed down a maximum distance of 0.2 cm below its
initial position, and it then rebounds. What is the loss in potential energy by the boy?
a. 800J
b. 1080J
c. 1600J
d. 1680 J
Answer:
c. 1600J
Explanation:
The loss in potential energy of the boy is given by:
[tex]U=mg \Delta h[/tex]
where
m = 40 kg is the mass of the boy
g = 9.8 m/s^2 is the acceleration of gravity
[tex]\Delta h = 4 m + 0.02 m = 4.02 m[/tex] is the total change in the height of the boy (4 metres + 2 cm due to the compression of the spring)
Substituting, we find
[tex]\Delta U = (40 kg)(9.8 m/s^2)(4.02 m) = 1577 J \sim 1600 J[/tex]
Read about Pendulums. Then complete the sentences based on the diagram of the pendulum. Be sure to keep this
article open because there will be several questions related to it.
The pendulum has the most potential energy
The pendulum has the least kinetic energy
The pendulum has the most kinetic energy at the top of swing
The pendulum has the least potential energy
Answer:
1. at the top of swing 2. at the top of swing 3. at the bottom of swing 4.at the bottom of swing
Explanation:
Answer:
The pendulum has the most potential energy at the top of swing.
The pendulum has the least kinetic energy at the top of swing.
The pendulum has the most kinetic energy at the bottom of swing.
The pendulum has the least potential energy at the bottom of swing.
The wind pushes a cup along the sand at the beach. The force of the wind was 17.8N, and the opposing force was 2N. If the cup accelerates at 7m/s^2, how much does the cup weigh?
Explanation:
Let's begin with the cup's free body diagram (figure attached), there we are able to see the forces acting on this object:
On the X axis:
[tex]F_{x}=F_{1}+F_{2}[/tex] (1)
Where:
[tex]F_{1}=17.8N[/tex] is the force of the wind
[tex]F_{2}=-2N[/tex] is the opposing force (that is why it has the negative sign)
So:
[tex]F_{x}=17.8N-2N=15.8N[/tex] (2)
In addition we know by Newton's 2nd law:
[tex]F_{x}=m.a[/tex] (3)
Where:
[tex]m[/tex] is the mass of the cup
[tex]a=7m/s^{2}[/tex] is its acceleration
Substituting (2) in (3):
[tex]15.8N=m(7m/s^{2})[/tex] (4)
Finding [tex]m[/tex]:
[tex]m=\frac{15.8N}{7m/s^{2}}=2.25kg[/tex] (5)
On the other hand we have the forces acting on the Y axis:
[tex]F_{y}=N-W=0[/tex] (6)
Where:
[tex]N[/tex] is the normal force
[tex]W=m.g[/tex] is the weight of the cup, being [tex]g=9.8m/s^{2}[/tex] the acceleration due gravity
This means:
[tex]N=W=m.g[/tex] (7)
Substituting (5) in (7):
[tex]W=(2.25kg)(9.8m/s^{2})[/tex] (8)
Finally:
[tex]W=22.05N[/tex] This is the weight of the cup
Both mechanical and electromagnetic waves _____. have compressions and rarefactions oscillate in the same direction as the wave motion transmit energy require a medium for transfer
Answer:
transmit energy
Explanation:
Waves (both mechanical and electromagnetic) are periodic perturbations of the space that transmit energy without transmitting matter. (so, "transmit energy" is valid for both types of waves).
The other statements are wrong because:
have compressions and rarefactions --> this is a property only of longitudinal waves, while electromagnetic waves are transverse, so they do not have compressions
oscillate in the same direction as the wave motion --> this is the description of longitudinal waves, while electromagnetic waves are transverse,
require a medium for transfer --> this is true only for mechanical waves: electromagnetic waves in fact do not need a medium to propagate.
Answer:
Both mechanical and electromagnetic waves transmit energy .
I hope this really helps!!!
Acceleration involves a change in speed or what?
Answer:
Velocity would be your answer.
answer please 98 points also brainliest
the answer is D) The air in the aquarium is saturated
none of the other answers were realistic AND I took this before so I know the right answer.
Answer:
d.
Explanation:
Look at it this way, when a sponge is saturated it cannot take in any more water. When air (a mixture of gasses) is saturated it cannot take in any more water vapour and water vapour will condense out as liquid water. This is termed the saturation point.
Air is classed usually as a percentage of saturation, dry air being 0% and saturated 100%
However, unlike the sponge ananalogy, 1kg of air will have a different capacity for water vapour depending on its temperature (and pressure). Charts (Psycrometric Charts) are available that allow the degree of saturation to be calculated, usually by determining the dew point (temperature at which 100% saturation occurs) by using a wet bulb thermometer and comparing it with the normal dry bulb temperature.
Which of the following describes an electric motor?
Check all that apply.
A.) Changes electric energy to mechanical energy.
B.) Can be powered by a hand crank.
C.) Uses the interaction between a spinning coil of wire and magnet.
D.) Is found in many appliances with moving parts, like a vacuum cleaner or a blender.
An electric motor changes electrical energy into mechanical energy, often found in household appliances like vacuum cleaners or blenders. They use the interaction between a spinning coil of wire and a magnet.
Explanation:An electric motor is a device that transforms electrical energy into mechanical energy. This is accomplished through the interaction between a spinning coil of wire and a magnet, a mechanism called electromagnetic induction. Many common appliances with moving parts, such as vacuum cleaners or blenders, contain electric motors in their design to facilitate desired functionalities, such as rotation or movement.
Option B, which suggests an electric motor can be powered by a hand crank, is incorrect. This describes a manual or mechanical system, not an electric motor.
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Electric motors convert electrical energy into mechanical energy through magnetic interactions.
Electric motors are devices that convert electrical energy into mechanical energy. They operate based on the interaction of magnetic fields and current-carrying conductors, generating force to produce motion. Electric motors are commonly found in various applications like industrial fans, household appliances, power tools, and more.
When you enter a pool of water, you feel as though you weigh less. What
causes this apparent change of weight?
A. Buoyant force
B. Cohesive force
C. Adhesive force
D. Pressure
Answer:
Buoyant force.
Explanation:
When we are immersed in a pool of water, we experiences a force pushing us in upward direction due to which our weight is decreased and this force is called Buoyant force.
This is also called upthrust.
Answer: Buoyant force
Explanation:
when a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false
Answer:
False
Explanation:
Gravity and impact puts a toll on it.
Francois places a ring made of an unknown metal into a graduated cylinder.
The water level in the graduated cylinder rises from 10.0 cm to 11.5 cm. He
has already found that the mass of the ring is 16.5 g. What is the density of
the ring?
O A. 1.7 g/cm
O B. 0.09 g/cm3
O C. 11.0 g/cm
O D. 1.4 g/cm3
The density of the ring is calculated by dividing its mass (16.5 g) by its volume (1.5 cm^3). The resulting density is 11.0 g/cm^3.
Explanation:The density of an object can be calculated by dividing its mass by its volume, according to the formula Density = Mass/Volume. In this case, Francois found the mass of the ring is 16.5 g. The volume can be determined by the displacement of water in the graduated cylinder, which is 11.5 cm - 10.0 cm = 1.5 cm3. Now we can calculate the density using the given values: Density = 16.5 g / 1.5 cm3 = 11.0 g/cm3. So, the option C, 11.0 g/cm is the correct answer.
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how much heat is absorbed by a 72g iron skillet when its temperature rises from 11°c to 23°c?
A good hypothesis must be which of the following
Answer:
Testable
Explanation:
A good hypothesis must always be testable.
Answer:
Must be testable and falsifiable
what is the efficiency of an engine that does 80 j of work and exhausts 320 j of heat while taking in 400 j of heat ?
a. 10%
b. 20%
c. 80%
d. 25%
Answer:
b. 20%
Explanation:
Efficiency of an engine is a ratio in percentage of the work done to the energy intake of the engine.
η=(Q₁-Q₂)/Q₁×100%
η is efficiency, Q₁ is the energy intake, Q₂ is energy wasted.
The information provided is:
Energy intake = 400 J
Work done = 80 J = (400-320) =Q₁-Q₂
Energy wasted =320 J
η= 80/400×100%
=20%
Answer:
B.20 %
Explanation:
20pts.
The edge of a flying disc with a radius of 0.13 m spins with a tangential speed of 33 m/s
The centripetal acceleration of the edge of the disc is?
Answer:
84 m/s2.
Explanation:
A. 0.0051
B. 0.43
C. 25
D. 84
Answer:
84 m/s^2
Explanation:
What is the primary force that helps suspension bridges use cables to hold their spans up? A. tension force B. resistance force C. normal force D. elastic force E. applied force
Answer:
A. Tension force
Explanation:
These are bridges that use cables to hold the road way up.
The cables in a suspension bridge receive the tension force of the bridge. These cables transmit these forces to the towers supporting the bridge and are compressed into the ground.
Answer:
The correct answer is option A. "tension force".
Explanation:
Suspension bridges, like the Golden Gate Bridge or the Brooklyn Bridge, use tension force as the primary source of force that cables use to hold their spans up. The supporting cables receive the tension forces of the bridge, and this same force passes to the anchorages and into the ground. This equilibrium that the tension force gives among the different elements of the bridge, gives the support to hold the bridge together.
Ella uses a camera as a model of the eye. The film in the camera serves the same role as which part of the eye?
lens
pupil
sclera
retina
Answer is :
retina- last choice
The film in a camera serves the same role as the d) retina in the eye.
Both the film and the retina are responsible for capturing images. In a camera, light enters through the lens, passes through the aperture (similar to the pupil), and is focused onto the film, where the image is recorded. Similarly, in the human eye, light passes through the cornea and lens, is focused by the lens, and hits the retina at the back of the eye.
The retina contains photoreceptor cells that convert the light into electrical signals, which are then sent to the brain for processing, forming the image we see. Therefore, the film in the camera acts as the light-sensitive part that captures and stores the image, just like the retina functions as the light-sensitive layer that detects and processes visual information in the eye.
VEICUL HC CICLE MICI.
Why is it important to warm up your muscles before a workout?
Answer:
You could become injured.
Explanation:
It is important to warm up your muscles before a workout because if you didn't you could pull a muscle or become seriously injured.
Answer:
To decrease your chance of injury
Explanation:
A(n)
such as oxygen or carbon, is a pure substance.
Answer:it is a pure substance
Explanation:
All elements are pure substances because they are made up of only one type of atom
Answer: An element is the answer you’re looking for!
A boat has a mass of 20 kg and will carry 110 kg of passengers across a pool. If 50% of the boat is submerged, what is the total volume of the boat?
Answer:
0.26 m³
Explanation:
There are three forces on the boat: weight of the boat, weight of the passengers, and buoyancy.
∑F = ma
B - mg - Mg = 0
Buoyant force is equal to the weight of the fluid displaced.
ρVg - mg - Mg = 0
ρV - m - M = 0
V = (m + M) / ρ
Given m = 20 kg, M = 110 kg, and ρ = 1000 kg/m³:
V = (20 + 110) / 1000
V = 0.13 m³
Since this is half of the boat's volume, the total volume is 0.26 m³.
The total volume of the boat is 0.0265 cubic meters.
What is Archimedes' principle?Archimedes' principle, which states that the buoyant force on an object immersed in a fluid is equal to the weight of the fluid displaced by the object.
Here in the Question,
Let's begin by finding the weight of the water displaced by the submerged part of the boat. Since we know that 50% of the boat is submerged, we can assume that the volume of water displaced is equal to half of the volume of the boat.
The weight of the water displaced can be found using the density of water, which is 1000 kg/m³. The formula for the weight of water displaced is:
Weight of water displaced = density of water x volume of water displaced x gravitational acceleration
where gravitational acceleration is 9.8 m/s².
Let V be the total volume of the boat. Then, the volume of water displaced is V/2, since 50% of the boat is submerged.
The weight of the boat is 20 kg, and the weight of the passengers is 110 kg. Therefore, the total weight of the boat and passengers is:
Total weight = weight of boat + weight of passengers
Total weight = 20 kg + 110 kg
Total weight = 130 kg
Now we can use Archimedes' principle to find the buoyant force on the boat:
Buoyant force = weight of water displaced = density of water x V/2 x gravitational acceleration
The buoyant force must be equal to the weight of the boat and passengers for the boat to float, so we have:
Buoyant force = Total weight
Substituting the values we have found, we get:
density of water x V/2 x gravitational acceleration = 130 kg x gravitational acceleration
Simplifying and solving for V, we get:
V = 130 kg / (density of water x 9.8 m/s² x 0.5)
Substituting the value of the density of water, we get:
V = 130 kg / (1000 kg/m³ x 9.8 m/s² x 0.5)
V = 0.0265 m³
Therefore, the total volume of the boat is approximately 0.0265 cubic meters.
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Which statement correctly describes the current in a circuit that is made up of any two resistors connected in parallel with a battery?
A. the current in the battery and in each resistor is the same
B. The current the battery equals to the sum of the currents in the resistors
c.The current in the battery is less than the current in either resistor
d. The current in the battery equals to the product of the currents in the resistors
B. The current the battery equals to the sum of the currents in the resistors describes the current in a circuit that is made up of any two resistors connected in parallel with a battery
What is a parallel combination ?
When two or more resistances are connected between the same two points, they are said to be connected in parallel combination
Resistors are connected in parallel combination , and its been known that if resistors are connected in parallel combination than current gets divided in each branch according to the value of resistance attached in that branch and voltage remains same across each resistance .
Also total current in the circuit or current in the battery is equal to the algebraic sum of current in each branch of the circuit
correct answer will be B. The current the battery equals to the sum of the currents in the resistors
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The coefficient of static friction between car's tires and a level road is 0.80 If car to be stopped in time of 3.0 sec its speed is
Answer:
23.5 m/s
Explanation:
The velocity of the car in decelerated motion is given by
v = u + at
where
v = 0 is the final velocity
u is the initial velocity
a is the acceleration of the car
t = 3.0 s is the time it takes for the car to stop
The acceleration of the car is given by the frictional force, which is the only force acting on the car along the direction of motion, so:
[tex]ma = -\mu mg\\a = -\mu g = -(0.80)(9.8 m/s^2)=-7.84 m/s^2[/tex]
where
[tex]\mu=0.80[/tex] is the coefficient of friction
Solving the previous equation for u, we find the initial velocity:
[tex]u=v-at=0-(-7.84 m/s^2)(3.0 s)=23.5 m/s[/tex]
12. A body is a particular amount of matter. It can be a solid, liquid or gas. It can be described as existing in
A. size and shape.
B. motion and force
C. time and space.
D. location and movement.
Answer:
A body is a particular amount of matter. It can be a solid, liquid or gas. It can be described as existing in time and space.
Explanation:
Answer:
c. Time and space.
Explanation:
A body is a particular amount of matter. it can be solid,liquid or gas. It can be described as existing in Time and space.
25 points, plus brainiest if answer is correct. Please i don't have much time.
Electromagnetic waves who's photons carry the highest energy also have the:
A.) shortest wavelengths
B.) strongest positive charges
C.) lowest frequency
D.) highest amplitude
Cereal plants gain chemical potential energy as they grow. Which form of energy is converted to create the chemical potential energy?
The plant absorbs the sunlight which serves as source of energy for the plant. Therefore, the form of energy which gets converted to “chemical potential energy is the solar energy”.
Explanation:
In process of photosynthesis, the plant makes the food and release oxygen, this occurs only in presence of solar energy that is sunlight. Therefore, the source of energy for the plants are sunlight which provides solar energy which is used up in energy conversion through various process.
The end product of the energy resource is the conversion to chemical potential energy gained over the growth of the cereal plants.
Acid rain is a secondary pollutant.
T or F
Answer: True
Explanation:
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