Analyze Energy Using Conservation Laws Practice Test

A 3.0 kg block is launched by a spring (spring constant $k=200\ \text{N/m}$) compressed by 0.30 m on a frictionless horizontal surface. What speed does the block have just after leaving the spring?

Use $PE_{spring}=\tfrac12 kx^2$ and $KE=\tfrac12 mv^2$.

A 2.0 kg ball is dropped from 10 m and bounces straight back up to 6.0 m. Take $g=10\ \text{m/s}^2$. How much energy was transformed into thermal/sound energy during the bounce?

Assume the ball’s kinetic energy just before impact is $mgh$ and just after leaving the ground is the energy needed to rise to 6.0 m.