Question

a boy of mass 40 kg is running down from third floor of a building which is at a height of 16 metre to the first floor which at a height of 8 metre calculate the change in potential energy and the speed at which he is running​

Answer 1

Answer:

mass of boy=40kg

height given=16mtr

let assume acceleration due to gravity=10m/s^2

therefore change in Potential energy=mgh=40x10x16=6400 Joule

Answer 2

Answer:

Pe will be halved and speed will decrease in turns and average speed will be same

Explanation:

AS THE PE=MGH AND PE1= MGH/2

THERE IS NO INFORMATION REGARDING THE STAIRS OR SLANT RUNWAY SO ITS DIFFICULT TO DETERMINE SPEED

THE PE AT 3RD FLOOR IS 9.8MS-1 × 40 × 16= 6272 JOULES AND PE1 AT 1ST FLOOR IS 9.8MS-1 × 40 × 8 = 3136