Question

A 15 kg object is gently lowered down a distance of 2.5 m. What was the work the force of gravity did on the object? Report your answer in SI units, rounded to the nearest whole number.

Can you please put into nearest whole number. Thank you and stay stay!

Answer 1

The work done by gravity when a object is moved through some height h is given by;

W = mgh ...........eqn 1

where m is the mass of the body; g is the acceleration due to gravity and h is the height through which the body is moved.

In the given question; mass of the body, m = 15 kg

Acceleration due to gravity, g = 9.8 m/s2

and Height through which the body is moved; h = 2.5 m

Hence,using these values in eqn 1, we get

W = 15*9.8*2.5

W = 367.5 J

Hence, work done by gravity on body of mass 15 kg when it is moved through a height of 2.5 m is given by 367.5 J

According to the signifcant figures theory; presence of 5 after the decimal either increases or decreases the value by 1 which is completely optional whether we consider it by increasing or decreasung the whole number value by 1.

For simplicity, we would take the value as decreased by 1 i.e W = 367 J

So, W = 367 J