a pogo stick has a magnet in its stroke and a spring in the

Solution

Work: The product of the component of the force exerted on an object in the direction of displacement and the magnitude of the displacement. work (force)(displacement) or W Fd The SI unit for work is the joule (J), which equals one newtonmeter (Nm). For maximum work to be done, the object must move in the direction of the force. If the object is moving at an angle to the force, determine the component of the force in the direction of motion. Remember, if the object does not move, or moves perpendicular to the direction of the force, no work has been done. Vocabulary Power: The rate at which work is done. power or P The SI unit for power is the watt (W), which equals one joule per second (J/s). One person is more powerful than another if he or she can do more work in a given amount of time, or can do the same amount of work in less time.

Solved Examples Example 1: Bud, a very large man of mass 130 kg, stands on a pogo stick. How much work is done as Bud compresses the spring of the pogo stick 0.50 m? Solution: First, find Bud’s weight, which is the force with which he compresses the pogo stick spring. Given: m 130 kg Unknown: w ? g 10.0 m/s2 Original equation: w mg Solve: w mg (130 kg)(10.0 m/s2) 1300 N Now use this weight to solve for the work done to compress the spring. W ¢t work elapsed time