Question about (KINETIC ENERGY AND WORK)

In summary, the conversation includes two multiple choice questions about calculating the rate of work done by a 50-N force on a 2-kg object. The first question involves calculating the power after 2 seconds of the force acting on the object, and the second question involves calculating the power at the moment the object has traveled 2m. The other options for each question were listed as well.
  • #1
Lord Dark
121
0

Homework Statement


hi guys how are you?? ,, there are 2 MC (Multiple choices question)
1- A 50-N force is the only force on a 2-kg object that starts from rest. When the force has been acting for 2 s the rate at which it is doing work is:(Ans:2500W)

2-A 50-N force is the only force a 2-kg crate that starts from rest. At the instant the object has gone 2m the rate at which the force is doing work is:(Ans:500W)

The Attempt at a Solution


i tried several ways but the problem is i know only 2 equations about power
one is P=W/t and P=Fv ,, in problem 1 there is no distance and in 2 there is no velocity, i didn't understand the questions in the first place(cant imagine it) ,, is the force acting horizontally or vertically ,, can anyone help me please before the exam,,
 
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  • #2
For the first one, you can calculate the distance based on the information given. Note that the object is in something like freefall, since the 50N force is the only thing acting on it.
 
  • #3
thanks ,, first one solved :) ,, still with the second...
 
  • #4
Lord Dark said:

Homework Statement


hi guys how are you?? ,, there are 2 MC (Multiple choices question)
1- A 50-N force is the only force on a 2-kg object that starts from rest. When the force has been acting for 2 s the rate at which it is doing work is:(Ans:2500W)

2-A 50-N force is the only force a 2-kg crate that starts from rest. At the instant the object has gone 2m the rate at which the force is doing work is:(Ans:500W)

Just curious what the other multiple choices were.
 
  • #5
LowlyPion said:
Just curious what the other multiple choices were.

in 1)
A. 75W
B. 100W
C. 1000W
D. 2500W
E. 5000W

2)
A. 2.5W
B. 25W
C. 75W
D. 100W
E. 500W
 

1. What is kinetic energy?

Kinetic energy is the energy that an object possesses due to its motion. It is a scalar quantity that depends on the mass and velocity of the object.

2. How is kinetic energy calculated?

Kinetic energy is calculated using the formula KE = 1/2 * m * v^2, where m is the mass of the object and v is its velocity.

3. What is the relationship between kinetic energy and work?

The relationship between kinetic energy and work is that work done on an object by a force is equal to the change in the kinetic energy of the object. In other words, when work is done on an object, it gains kinetic energy, and when work is done by an object, it loses kinetic energy.

4. How is kinetic energy related to potential energy?

Kinetic energy and potential energy are both forms of mechanical energy. Kinetic energy is the energy an object possesses due to its motion, while potential energy is the energy an object possesses due to its position or configuration. In some cases, potential energy can be converted into kinetic energy and vice versa.

5. How does the mass and velocity of an object affect its kinetic energy?

The mass and velocity of an object have a direct effect on its kinetic energy. As the mass of an object increases, its kinetic energy also increases. Similarly, as the velocity of an object increases, its kinetic energy increases at a faster rate, as it is directly proportional to the square of the velocity.

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