Question

How many joules are expended by a 70 kg man climbing up 6m of stairway? How much work is done if the climbing takes place on the surface of the moon? (Assume that the acceleration due to gravity on the moon’s surface is 1.6 m/s2

Answer 1

Answer:

On the earth surface ,W= 4200 J

On the moon surface ,W= 672 J

Explanation:

Given that

mass of the man ,m = 70 kg

Height of the stairway ,h= 6 m

On the earth surface :

We know that acceleration due to gravity at earth ,g= 10 m/s²

The work done by man is given as

W= m g h

Now by putting the values in the above equation we get

W= 70 x 10 x 6 J

W=4200 J

On the moon  surface :

The gravity on the moon ,g= 1.6 m/s²

The work done W

W= 70 x 1.6 x 6 J

W=672 J

On the earth surface ,W= 4200 J

On the moon surface ,W= 672 J