Quiz 9:

1. SI unit of work expressed in terms of fundamental units of mechanics is equal to ...

2. An object is displaced by a distance of 40 m horizontally by a 600 force that makes an angle of 20 deg with the horizontal. Calculate the wrk done by the force.

3. An object is being pulled to the left by a 280 N force that makes an angle of 30 deg with the horizontal-left while moving to the right for a distance of 80 m. Calculate the work done by the force.

4. A 5 kg object is displaced to the right by a distance of 10 m under the influence of the following forces: a 20 N vertical force pushing on the object downwards, a 16 N force that makes an angle of 50 deg with the horizontal-right. Calculate the net work done on the object.

5. Calculate the speed of an object of mass 12.233 kg if its kinetic energy is 1600 J.

6. Under the influence of some forces, the speed of a 30 kg object changed from 5 m ⁄ s to 90 m ⁄ s. Calculate the net work done by the forces.

7. In which of the following situation is the change in motion not caused by a conservative force?

8. Under the influence of a conservative force, an object is displaced from a location where its potential energy is 1000 J to a location where its potential energy is 350 J. Calculate the work done by the conservative force.

9. An object of mass 10.433 kg has a mechanical energy of 120 J as it passes a location where its potential energy is 21 J. Calculate its speed as it passes this location.

10. 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 respectively 56.777 J and 100.467 J. Its kinetic energy at point B is 5 J. Calculate its potential energy at point B.

11. Under the influence of conservative forces only, an object of mass 15 kg is displaced from point A to point B. Its potential energy and speed at point A respectively are 950 J and 14 m ⁄ s. Its potential energy at point B is -800 J. Calculate its speed at point B.