Question

A body is released from rest at point A. Find the separation between B and C.​

Answer 1

answer : option (1) 40m

explanation : This question is based on work - energy theorem.

potential energy at point A = kinetic energy at point B + potential energy at point B

or, Mg(60m) = 1/2 Mv² + Mg(40m)

or, g(60 - 40) = 1/2 v²

or, v² = 40g

put g = 10m/s² , v² = 400

or, v = 20m/s

now we have to find seperation (horizontal distance) between B and C.

it seems a particle moves in horizontal projectile from height of 40m with speed 20m/s .

so, time taken to reach ground , t = √{2h/g} = √{2 × 20/10} = 2sec

so, horizontal distance , x = ut = 20 × 2 = 40m

hence, answer should be 40m.

Answer 2

Answer:

it is 40(2)^1/2

Explanation:

you should now the free fall. where u=0 which is denoted as Uy . but here the body taken some horizontal speed Ux.Thank you!