Solve for the work and the Power output

Question

You are helping out by lifting hollow blocks, each with a mass of 1.5 kg, from the street to the cart that is 0.75 m high. (a) How much work do you perform in lifting each block? (b) If you can place 10 blocks on the cart every minute, what is the power output?

Answer 1

a) Work = Force * distance (in the same direction)

You are doing work against gravity to lift the box vertically. The force you are fighting is the force gravity aka the weight of the box, and the distance is 0.75m.

Weight = mass * gravity = 1.5*9.8 = 14.7N

Work = F * d = 14.7 * 0.75 = 11N to lift each box

b) Power = Work/time (but time must be in seconds)

needs to find out how many Joules of work are done by lifting 10 blocks in 1 minute.

Work 1 block = 11N * 10 blocks = 110N total work

time = 1 minute = 60 seconds

Power = Work/ time = 110/60 = 1.8Watts of power