1. State Newton's second law.
   1. An object will remain at rest or move in a straight line with a costant speed unless acted upon by a net force.
   2. Any two objects in the universe attract each other with a force directly proportional to the product of their masses and inversely proportional to the square of the distance separating them.
   3. The force acting on an object is inversely proportional to the acceleration produced by the force.
   4. The force acting on an object is directly proportional to the acceleration produced by the force.
   5. For every reaction, there is an equal but opposite reaction.
2. Calculate the force acting on a 6.443 kg object moving with an acceleration of 24 m s².
3. A force that causes an acceleration of 7 m s² on an object of mass 20.123 kg is acting on a 50 kg object. Calculate the acceleration of the 50 kg object.
4. The component of the surface force between two surfaces sliding on each other parallel to the surface is called
   1. friction
   2. gravitational force
   3. normal force
   4. contact force
   5. sliding force
5. An object of mass 48.678 kg is sliding on a horizontal surface with a uniform speed. The coefficient of kinetic fiction of the surfaces is 0.2. Calculate the force of friction exerted by the surface on the object.
6. An object of mass 18.333 kg is being pulled by a horizontal force of 210 N on a horizontal force. The coefficient of kinetic friction between the object and the surface is 0.45. Calculate the acceleration of the object.
7. An object is being pulled on a horizontal surface by a horizontal force of 300 N. If it s moving with a uniform speed, calculate the force of friction exerted by the surface on the object.
8. An object of mass 280 kg is being pulled on a friction less horizontal surface by means of two strings. One of the strings is pulling forward, has a tension of 600 N and makes an angle of 30 degree with the horizontal-right. The other string is pulling backwards horizontally and has a tension of 20 N. Calculate the acceleration of the object.
9. An object of mass 8 kg is being pulled on a horizontal surface by a string that makes an angle of 40 degree with the horizontal. The tension in the string is 17 N. Calculate the normal force exerted by the ground on the object.
10. A 16 kg object and a 7 kg object are attached by a string. If the 7 kg object is being pulled by a force of 220 N. Calculate their acceleration.
11. The SI unit of measurement for work is
    1. Volt
    2. Coloumb
    3. Joule
    4. Pascal
    5. Newton
12. An object is being pulled to the left by a 80 N force that makes an angle of 70 deg with the horizontal-left while moving to the right for a distance of 50 m. Calculate the work done by the force.
13. Calculate the speed of an object of mass 42.333 kg if its kinetic energy is 1800 J.
14. Under the influence of some forces, the speed of a 21.325 kg object changed from 6 m s to a certain speed. If the net work done on the object is 1450 J, Calculate its final speed.
15. An object has a kinetic energy of 120 J as it crosses a location where its potential energy is 19 J. Calculate its mechanical energy as it crosses this location.