6. Which type of friction acts on an object when it moves through a fluid?
a) Static friction
b) Rolling friction
c) Sliding friction
d) Fluid friction
7. Which of the following statements is true about the coefficient of friction?
a) It depends on the area of contact between two surfaces
b) It is always a positive value
c) It is a measure of how rough or smooth the surfaces are
d) It is independent of the weight of the object
8. Which of the following factors does not affect the coefficient of friction between two surfaces?
a) Temperature
b) Weight of the object
c) Surface area of contact
d) Roughness of the surfaces
9. Which of the following statements is true about Newton’s first law of motion?
a) An object at rest remains at rest, and an object in motion remains in motion with a constant velocity unless acted upon by an external force
b) The force acting on an object is equal to the mass of the object times its acceleration
c) For every action, there is an equal and opposite reaction
d) The rate of change of momentum of an object is directly proportional to the net force applied to it
10. Which of the following is an example of an external force?
a) Gravity
b) Friction
c) Air resistance
d) Applied force
