Question

Two balls A and B of same masses are thrown from the top of the building. A, thrown upward with velocity V and B, thrown downward with velocity V, then

Answer 1

Velocity of A is more than B at the ground

Velocity of B is more than A at the ground

Both AandB strike the ground with same velocity

None of these

Answer :

C

Solution :

Let both the balls are thrown from height 'h', both will move under same acceleration i.e., acceleration due to the gravity.

Let the speed of ball 'A' when it reach the ground is VA.

For ball A using v2=u2+2gh

(VA)2=V2−2gh⇒VA=V2−2gh−−−−−−−−√

Let the speed of ball 'B' when it reach the ground is VB.

For ball 'B' again using v2−u2+2gh

(VB)2=(−V)2−2gh⇒VB=V2−2gh−−−−−−−−√.