Question

a stair is at 60 degree angle with roof. a man of 60 kg with 20 kg bag is using stair to go to roof. how much work he does?if he used the stair perpendicularly , how much work he did?

does both work same??
if same then why?

Answer 1

Answer on Question #50776, Physics, Mechanics | Kinematics | Dynamics

A stair is at 60 degree angle with roof. A man of 60 kg with 20 kg bag is using stair to go to roof. How much work he does? If he used the stair perpendicularly, how much work he did?

Does both work same??

If same then why?

Solution:

The potential energy (PE) possessed by an object is the amount of work the object is capable of doing because of its position.

Work Done Against the Force of Gravity

$$W = mgh$$

m = 60+20 = 80 kg – mass of the object;

g = 9.81 m/s² – gravitational acceleration;

h = ? – height of the object from the original position;

Work done in two cases is the same, because vertical height h of the motion is the same.

Answer:

Work done in two cases is the same, because potential energy possessed by the object is the same.