Question

Croquet balls must have a mass of 0.50 kg. A red croquet ball, moving at 10

m/s, strikes an at-rest green croquet ball head-on. The red ball continues
moving at 1.5 m/s after it hits the green ball. What is the final speed of the
green ball?
O A. 5 m/s
B. 8.5 m/s
C. 1.5 m/s
O D. 15 m/s
SUS

Answer 1

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

Further explanation

Given

mass of Croquet ball = 0.5 kg

v₁= 10 m/s

v₁'= 1.5 m/s

Required

the final speed

Solution

The law of conservation of momentum

m₁v₁ + m₂v₂ = m₁v₁ '+ m₂v₂' (1=red croquet ball, 2=green croquet ball)

v₂=0 (at rest)

Input the value :

`\tt 0.5* 10+0.5* 0=0.5* 1.5+0.5* v_2'\\\\5=0.75+0.5v_2\\\\4.25=0.5v_2\rightarrow v_2=8.5~m/s`