Question

A body fall from 40 m it's velocity after 2 s is
A
40 ms-1
B
20 ms-1
с
10 ms-1
D
5 ms-1​

Answer 1

Answer:

A) 40 m/s

Explanation:

initial velocity (u) : 0

time (t) : 2 sec

distance (s) : 40 m

final velocity (v) : ?

2nd equation of motion : S=1/2 at²

40=1/2 a×2²

40=1/2 a×4

40=a×2

40/2=a

20=a

a=20 m/s²

1st equation of motion : v=u+at

v=0+20×2

v=40 m/s