Question

A 30kg mass moving at 18.0 m/s collides with a 90kg mass moving at 14.4 m/s in the opposite direction. The collision is elastic and head on. Find the velocity of each mass after the collision.

Answer 1

Answer:

m1 = 30 kg,

m2 = 90 kg,

u1 = 18.0 ms^−1,

u2 = -14.4 ms^−1.

Let the velocities of m1 and m2 after the collision be v1 and v2.

By law of conservation of linear momentum,

m1u1 + m2u2 =m1v1 + m2v2 .

As the collision is elastic, by law of conservation of kinetic energy,

1/2m1u1^2 + 1/2m2u2^2

=1/2 m1v1^2 + 1/2m2v2^2.

So, v1 = (m1−m2/m1+m2)u1 + ( 2m2/m1+m2)u2

= ( 30−90/30+90 )18.0 + ( 2X90/30+90 )(- 14.4)

= -30.6 ms^−1

.

v2 =( 2m1/m1+m2)u1 + (m2−m1/m1+m2)u2

= ( 2X30/30+90 )18.0 + ( 90−30/30+90 )(- 14.4)

= 1.8 ms^−1.

See the picture too.

Hope this helps you.

Thank You.❤

Answer 2

Answer:

I hope it helps you.