Question

If you tossed an object either up or down and could somehow eliminate the effects of air on its flight you would find that the object accelerates downward at a certain constant rate. The rate is called the free fall acceleration and its magnitude is represented by g. The acceleration is independent of the objects characteristics such as mass density or shape it is the same for all objects.

A: when an object is placed on a surface the frictional force between the surface and the object is more if the mass of the object is heavy. R: static friction is directly proportional to normal reaction.

Whenever a body moves or tends to move over the surface of another body, a force comes into play which acts parallel to the surface of contact and opposes the relative motion. This opposing force is called friction. Static friction fS opposes the impending relative motion while the kinetic friction fK opposes the actual relative motion. Static friction is a self-adjusting force. The maximum value of static friction (fS=μsN) which comes into play when a body just starts moving over the surface of another body is called limiting friction. fs ≤ μsN and fk = μkN where N is the normal reaction between the two surfaces in contact. Both static and kinetic friction are independent of the area of surfaces in contact.

A ball is dropped from height h. The velocity attained by the ball just before reaching the ground is