Elastic and inelastic collisions

Answer Key - Grade 11 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Using KE = ½mv², what is the kinetic energy of a 2 kg cart moving at 3 m/s, Ari?

   9 J
2. 2.

   Using KE = ½mv², what is the kinetic energy of a 4 kg cart moving at 2.5 m/s, Bo?

   12.5 J
3. 3.

   Using KE = ½mv², what is the kinetic energy of a 0.5 kg cart moving at 8 m/s, Esme?

   16 J
4. 4.

   In the charts, is kinetic energy conserved, Kira?

   • No: collisions destroy energy
   • No: cart A's 8 J is gone
   • Yes: 8 J before and after
5. 5.

   What makes a collision elastic, Milo?

   • The carts stick together
   • Kinetic energy is conserved
   • Momentum is lost in the collision
6. 6.

   In an inelastic collision, what is NOT conserved, Noah?

   • The total kinetic energy
   • The total momentum
   • The total mass
7. 7.

   Two carts stick together after colliding. What is this kind of collision called, Pia?

   • Elastic, since they move together
   • Perfectly inelastic
   • Super-elastic
8. 8.

   Two carts collide with a loud clack and slow down more than in a bounce. Where did the missing kinetic energy go, Ren?

   • Sound, heat and bending
   • It turns into extra momentum for both carts
   • It was destroyed
9. 9.

   A clay ball hits a cart and sticks, leaving a dent. Where did some of the kinetic energy go, Tala?

   • Nowhere; it vanished
   • Into the clay's mass
   • Into denting and warming the clay
10. 10.

    In an inelastic collision, what happens to the total energy, Zee?

    • It stays the same, in new forms
    • It gets used up
    • It doubles after the collision