Na-
4. main bicycle traveling along a road.
5. explain can there be forces acting on an object if the object is at
rest? must there be an unbalanced force acting on a moving
object? explain your answers.
6. explain why does coating surfaces with oil reduce friction
between the surfaces?
7. distinguish between the mass of an object and the object's weight.
8. think critically suppose earth's mass increased but earth's diame-
ter did not change. how would the gravitational strength near
earth's surface change?