Question

A $3.0kg$ bowling ball is moving to the left at $4.0m/s$. It collides in a perfectly elastic collision with a $6.0kg$ bowling ball moving to the right at $2.0m/s$. What is the total kinetic energy after the collision?

• A. $62J$
• B. $36J$
• C. $25J$
• D. $12J$
• E. $0J$

Answer 1

The correct option is B $36J$

Given - $m_1=3.0kg,m_2=6.0kg,v_1=4.0m/s,v_2=2.0m/s$

As it is a elastic collision therefore kinetic energy will not change after collision ,

kinetic energy before collision=kinetic energy after collision ,

$1/2m_1{v}_1^2+1/2m_2{v}_2^2=K_{after}$

or $1/2\times 3.0\times {4.0}^2+1/2\times 6.0\times {2.0}^2=K_{after}$

or $24+12=K_{after}$

or $K_{after}=36J$