Question

Write True or False. If False, rewrite the statement as a true.

9. When a collision occurs between two objects, the vector sum of the momenta changes.

10. All collisions conserve momentum and can be distinguished on the basis of whether they also

conserve kinetic energy.

11. During a hockey game, a stationary goalie stops a puck. If we know his kinetic energy after the save,

we can determine the initial kinetic energy of the puck.

12. When two bodies travelling toward each other at the same speed collide, the resultant velocity of

each body is different.

13. In reality, collisions between heavy objects can only be approximately elastic.

14. A curling stone hits a wall at a right angle and rebounds with a final speed that is nearly equal to its

initial speed. Its final path will almost be the mirror image of its initial path.

Answer 1

Answers :

Question (9) Answer : False

Because, According to the conservation of momentum : Momentum is always conserved in any collision.

Question (10) Answer : True

Because, According to the conservation of momentum : Momentum is always conserved in any collision. And, Type of collision (Elastic or Inelastic) depends on whether kinetic energy is conserved or not.

Question (11) Answer : True

Becasue, Using momentum conservation principle - We can find the velocities of the puck and the Goalie. And, then using that values of velocities - We can find kinetic energy.

Question (12) Answer : True

Here, Resultant velocities will dpend on the masses of the objects. If the mass of both the objects are same then the final velocity will be Zero and if the masses of the objects are different then the resultant velocities of the objects will be different.

Question (13) Answer : False

In reality, any macroscopic collision between objects will convert some kinetic energy to internal energy and other forms of energy, so no large-scale impacts are perfectly elastic.

Question (14) Answer : False