An object travels down a ramp at a constant acceleration. The object experiences a force of friction and a gravitational force. Which of the following could be true about the motion of the object? a. The force of friction acts in the same direction as the object travels.
b. The force of friction between the surface and the object is less than the component of the gravitational force that is parallel to the ramp.
c. If the object increased in mass, the object's acceleration would change.
d. If the object increased in mass, the normal force exerted on the object would remain the same.

Option (b) is correct.

Explanation:

An object travels down a ramp at a constant acceleration.

Friction force and the gravitational force is there.

(a). It is false. As the friction acts in the opposite direction of motion of the object.

(b). It is true. As the object moves down the ramp so the force of friction is less the component of gravitational force along the ramp.

(c). It is false. the acceleration does not depends on the mass.

a = g sin A - u g cos A

where, A is the angle of inclination and u is the coefficient of friction.

(d). It is false. The normal force is given by

N = m g cos A

so it depends on the mass.

d) physical means can be used to separate the components of air.