Question

It takes Andy 0.50 seconds to lift a 98-newton box from the floor and place it on the table. If he expends a constant power of 137 watts during this time, what is the height of the table?

Answer 1

Work is the product of the force exerted and the distance that the object had moved in the direction of the force. Further, power is the rate at which this work is being done. From this,
P = (F x d) / s
Substituting the given values,
137 J/s = (98 N x d) / 0.50
The value of d in the equation is approximately 0.70 meters.

Answer 2

Power = Work done / time, Power = 137 watts, time = 0.5s

137 watts = Work done/ 0.5s

Work done =137 * 0.5 = 68.5 J

But Work done = Force * displacement, Force = 98 N

68.5 = 98 * displacement

68.5/98 = displacement

0.699 ≈ displacement

Height of table ≈ 0.70 m