Physics Help? 4

Question

A 20.0-g ball moving to the right at 27.0 cm/s makes a head-on elastic collision with a 60.0-g ball that is moving to the left at 36.0 cm/s. Find the speed of each ball and the direction it is traveling after the collision.

Answer 1

Step 1 :

Mass of the first ball is 20 g and is moving in right direction.

Velocity of the first ball is 27 cm/s.

Mass of the second ball is 60 g and is moving in left direction.

Velocity of the second ball is 36 cm/s.

After head-on elastic collision velocity of the first ball is .

Substitute m₁ = 20, m₂ = 60, v₁ = 27 and v₂ = 36.

The velocity of the first ball after collision is 40.5 cm/s.

Step 2:

After head-on elastic collision velocity of the second ball is .

Substitute m₁ = 20, m₂ = 60, v₁ = 27 and v₂ = 36.

The velocity of the second ball after collision is 31.5 cm/s.

Step 3:

Here , so the direction of first ball is opposite to its original direction.

Therefore the direction of first ball is left.

The direction of the second ball is unchanged.

The direction of the second ball is left.

Solution:

The velocity of the first ball after collision is 40.5 cm/s and is moving in left direction.

The velocity of the second ball after collision is 31.5 cm/s and is moving in left direction.