Question

APEX!!!! PLEASE HELP!!!!

A red croquet ball, moving at 8.5 m/s, strikes an at-rest green ball head on. If the red ball stops after hitting the green ball, what is the final speed of the green ball? Croquet balls must have a set mass of 0.50 kg

A. 17.5 m/s
B. 8.5 m/s
C. 4.25 m/s
D. 5 m/s

Answer 1

its B. 8.5 ..........(Apex)                        

Answer 2

The final speed of the green ball is 8.5 m/s

Step-by-step explanation:

Mass of croquet balls, m₁ = m₂ = 0.5 kg

Initial velocity of red croquet ball, u₁ = 8.5 m/s

Initially, the green ball is at rest, u₂ = 0

A head on collision takes place between two balls. The red ball stops after hitting the green ball.

Final velocity of red ball, v₁ = 0

Final velocity of green ball is v₂

Using the conservation of linear momentum as :

`m_1u_1+m_2u_2=m_1v_1+m_2v_2`

`0.5\ kg* 8.5\ m/s+0=0+0.5v_2`

v₂ = 8.5 m/s

So, the final speed of the green ball is 8.5 m/s. Hence, the correct option is (b) "8.5 m/s".