1. 2. Under the influence of conservative forces only, an object is displaced from point A to point B. Its potential energy and kinetc energy at point A are respectively52.666J and60.554J. Its kinetic energy at point B is 40J. Calculate its potential energy at point B.
   3. An object of mass12.333kg is located at the top of a24m tall building. Calculate the gravitational potential energy of the object with respect to a point1m below the top of the building .
   4. A roller coaster extends to the ground from a height of40m (point A) and then rises to a height of19m (point B). An object of mass2kg starts at point A with a speed of8m s. Assuming the roller coaster is friction less, calculate the speed of the object by the time it reaches point B.
   5. A spring extends by0.8m when an object of mass 3kg hangs from it. By how much will it extend when an object of mass14kg hangs from it.
   6. Work done by the non conservative forces acting on an object is equal
      1. to the change in the mechanical energy of the object
      2. to the change in the kinetic energy of the object
      3. to the work done by the conservative forces
      4. to the change in the potential energy of the object
      5. to the net work done on the object
   7. Intially an object has a potential energy of80J and a kinetic energy of190J. Under the influence of conservative and non-conservative forces its potential energy changed to30J and its kinetic energy changed to36J. Calculate the work done by the non-conservative forces.
   8. Calculate the momentum of an object of mass0.36kg moving with a speed of4.8m s.
   9. An object of mass0.16kg falling vertically downward hits the ground with a speed of12m s and bounces back vertically upward with a speed3m s. If the object was in contact with the ground for0.2seconds, calculate the average force exerted by the ground on the object.
   10. An object of mass9.5kg was acted by a force of24.2N for 0.6seconds. If its initial speed was2.0m s, calculate its final speed.
   11. An object of mass4kg moving with a speed of25m s to the right collides with an object of mass17kg moving with a speed of12m s to the left. After collision, the17kg object moves to the right with a speed of9m s to the right. Calculate the velocity of the4kg object after collision.
   12. An object of mass16kg moving with a speed of28m s to the right collides with an object of mass17kg at rest. If the collision is completely inelastic, calculate the kinetic energy lost during the collision.
   13. Which of the following statements is a correct statement.
       1. Colliding objects always lose kinetic energy during collision.
       2. All collisions where momentum is conserved are called completely elastic collisions.
       3. If colliding objects are treated as a single system, then the net force acting on the system is zero.
       4. A collision where both momentum and kinetic energy are conserved is called a completely inelastic collision.
       5. Kinetic energy is always conserved during a collision
   14. After a bullet of mass0.06kg is fired into a ballistic pendulum of mass1.5kg, the bullet is embedded in the pendulum and the pendulum rose to a height of0.25m. Calulate the speed with which the bullet was fired into the ballistic pendulum.
   15. An object of mass11kg going to the right with a speed of30m s collides with a(n)16kg object going to the left with a speed of5m s. If the collision is completely elastic, calculate the speed of the16kg object after collision.
   16. An object of mass21kg going to the right with a speed of21m s collides with a(n)10kg object at rest. After collision the21kg object moves with a speed of10m s making an angle of10degree with the horizontal-right. Calculate the x-component of the velocity of the10kg object after collision.