Name ____________________________

Forces and Friction Homework (pages 374-387)

_______________________ 1. A force that pulls all objects toward each other.

_______________________ 2. As distance between objects increases, what happens to

gravity?

_______________________ 3. True or False: All objects in the Universe are gravitationally

attracted to all other objects in the universe.

_______________________ 4. When you step on a bathroom scale, you are determining the

gravitational force Earth is exerting on your mass. What is

another way to describe what the scale is measuring?

_______________________ 5. The amount of gravity depends on the amount of:

_______________________ 6. When gravity is the only force acting on a falling object, the

object is said to be in:

_______________________ 7. When a feather slowly floats to the ground, a type of fluid

friction called _________ is acting on the feather to slow its fall.

_______________________ 8. An object that is thrown instead of dropped is called a

projectile. True or False: An object that is thrown straight

out (an object with projectile motion) will fall at the same

rate as an object that is dropped from the same height.

_______________________ 9. When two solid surfaces move past each other, this type of

friction resists the motion.

_______________________ 10. To decrease sliding friction, oil is added to some machinery.

This creates a different kind of friction that is less resistant

than sliding friction. What kind of friction is created when

oil is applied to machinery?

_______________________ 11. When you help your family move a heavy piece of furniture,

what kind of friction resists your initial attempts at moving

the furniture?

________________________ 12. A force that resists the movement between two surfaces.

________________________ 13. When the net force applied to an object causes a change in

velocity, the forces can be described this way:

________________________ 14. Equal forces acting on an object. The net force is zero and

there is no change in velocity.

________________________ 15. If two forces are applied to the same side of the box (in the

same direction) and the forces are both equal to 20N, what

is the net force acting on the box?

________________________ 16. A push or a pull that attempts to change the velocity of an

object.