# Mechanics: Work, Energy and Power

## Work, Energy and Power: Audio Guided Solution

#### Problem 22:

Paige is the tallest player on South's Varsity volleyball team. She is in spiking position when Julia gives her the perfect set. The 0.226-kg volleyball is 2.29 m above the ground and has a speed of 1.06 m/s. Paige spikes the ball, doing 9.89 J of work on it.

a. Determine the potential energy of the ball before Paige spikes it.
b. Determine the kinetic energy of the ball before Paige spikes it.
c. Determine the total mechanical energy of the ball before Paige spikes it.
d. Determine the total mechanical energy of the ball upon hitting the floor on the opponent's side of the net.
e. Determine the speed of the ball upon hitting the floor on the opponent's side of the net.

## Audio Guided Solution

Click to show or hide the answer!

## Habits of an Effective Problem Solver

• Read the problem carefully and develop a mental picture of the physical situation. If necessary, sketch a simple diagram of the physical situation to help you visualize it.
• Identify the known and unknown quantities in an organized manner. Equate given values to the symbols used to represent the corresponding quantity - e.g., vo = 0 m/s; a = 4.2 m/s/s; vf = 22.9 m/s; d = ???.
• Use physics formulas and conceptual reasoning to plot a strategy for solving for the unknown quantity.
• Identify the appropriate formula(s) to use.
• Perform substitutions and algebraic manipulations in order to solve for the unknown quantity.