Question

It takes 20 s for a person A to climb up the stairs, while another person B does the same in 45 s and both having same mass. Find

(a) Ratio of works done by A and B.

(b) Ratio of powers expended by A and B​

Answer 1

Answer:

Explanation:

Body A mass = M

height of stairs = H

Work Done = m*g*h = MgH (∵ work done = potential energy) - 1

P1 = MgH/20

Body B mass = M (Mass A = Mass B)

Height of Stairs =H

Work Done = MgH (∵ work done = potential energy) - 1

P2 = Mgh/45

1. divide i and ii

$\frac{MgH}{MgH}$ = 1:1

2.

$\frac{MgH/20}{MgH/45}$= $\frac{20}{45}$=$\frac{5}{9}$ = 5:9