Force and Laws of Motion

Topics in this chapter

• Inertia and First Law
• Balanced and Unbalanced Forces
• Force, Mass, and Acceleration
• Momentum and Impulse
• Conservation of Momentum
• Third Law and Action-Reaction
• Laws of Motion Applications

Cheat sheet

Practice questions

1. Question 1Q-1706D2

   Which of the following statements is true regarding a balanced force acting on an object?

   1. A.It changes the speed of the object.
   2. B.It changes the direction of motion of the object.
   3. C.It does not change the state of rest or uniform motion of the object.
   4. D.It always produces acceleration in the object.
   See the answer and solution
2. Question 2Q-C9EF9F

   When a hanging carpet is beaten with a stick, dust particles are removed from it. This phenomenon can be best explained by:

   1. A.Newton's first law of motion
   2. B.Newton's second law of motion
   3. C.Newton's third law of motion
   4. D.Law of conservation of momentum
   See the answer and solution
3. Question 3Q-1F6698

   What is the SI unit of momentum?

   1. A.kg m s^-2
   2. B.kg m s^-1
   3. C.N m
   4. D.kg m^2 s^-2
   See the answer and solution
4. Question 4Q-AA1A57

   A constant force acts on an object of mass 5 kg at rest for 2 seconds, giving it a velocity of 6 m s^-1. The magnitude of the force is:

   1. A.15 N
   2. B.30 N
   3. C.12 N
   4. D.7.5 N
   See the answer and solution
5. Question 5Q-BBEBAD

   According to Newton's third law of motion, action and reaction forces:

   1. A.Act on the same body and have opposite directions
   2. B.Act on different bodies in opposite directions and have equal magnitudes
   3. C.Act on different bodies in the same direction and have unequal magnitudes
   4. D.Cancel each other out completely because they are equal and opposite
   See the answer and solution