Question

After a large snowstorm, you shovel 2,500 kilograms of snow off of your sidewalk in half an hour. You lift the shovel to an average height of 1.5 meters while you are piling the snow in your yard.

a. How much work did you do? Hint: The force is the weight of the snow.
b. What was your power in watts? Hint: You must always convert time to seconds when calculating power.

Answer 1

For the calculation of total work, it doesn't matter whether you
add it up one shovelful at a time or all at once.

Work = (weight) x (height) = (mass) x (gravity) x (height)

= (2,500 kg) x (9.8 m/s² ) x (1.5 m)

= 36,750 joules .

Power = (work in joules) / (time in seconds)

1/2 hour = 1,800 seconds

Power = (36,750 joules) / (1,800 seconds) = 20.42 watts