Work Power And Energy

In an inelastic collision, kinetic energy is not conserved. Some of the initial kinetic energy is converted into other forms of energy such as heat, sound, and internal energy due to deformation. Thus, the kinetic energy after the collision is always less than the initial kinetic energy.

Step 1: Compute Work Done Against Gravity The work done in climbing the height is equivalent to the gain in potential energy: Substituting the values:
Step 2: Compute Power Output Power is defined as work done per unit time: The climber takes 90 minutes, which is: % Final Answer Thus, the correct answer is option (1): W.

Step 1: The work done by a variable force is given by the integral of the force over the displacement: Substitute the given force and limits and : Step 2: Now, solve the integral: Evaluating this from to : Thus, the work done by the force is 201 J.

The work done by friction is the force of friction times the distance the object travels. The force of friction is given by: The work done by friction is: Using the work
-energy theorem, we know that the work done by friction is equal to the change in kinetic energy. The initial kinetic energy is , and the final kinetic energy is zero because the particle comes to rest. Thus: The distance can be found from the equation . Now, the average power imparted by friction is the work done per unit time. The time taken to stop is: Thus, the average power is: Thus, the correct answer is .