Laws of Motion Study Guide
Acceleration- A change in an object’s velocity (speed).
Air resistance- A force of air which slows a moving object.
Balanced force- forces that are equal in size and opposite in direction (no
movement)
Force- A push or a pull that acts on an object that makes it move, change
direction, or stop its movement. Force is measured in Newtons, not kilograms or
pounds.
Friction- A force that happens between two objects that affects its motion. A
force caused by one object rubbing against another.
Gravity- The force that pulls two objects towards each other.
Inertia- the tendency of an object to resist change in its motion (not wanting to
change its motion)
Mass- The physical stuff or matter in an object.
Momentum- The force in a moving object. The more speed and mass an object
has the more momentum is has.
Motion- Any change in an objects location or direction.
Newton- The unit of measurement used to measure force. (N)
Unbalanced force- Unequal forces that act on an object from opposite sides
causing the object to move.
Weight- a measure of how strongly gravity pulls downwards
Work- Result of a force moving an object over a distance.
Isaac Newton- The British scientist that is known for his discoveries of gravity
and the three laws of motion.
Newton’s Three Laws of Motion:
1. First Law- (Law of Inertia) An object at rest will stay at rest and an object
in motion will stay in motion until acted on by an outside force.
2. Second Law- An object’s acceleration depends on its’ mass and the force
acting on it.
3. Third Law- For every force (action), there is an equal and opposite
reaction force.
**Be able to determine whether something is a balanced or unbalanced force.
Example: Two football players that are the same size tackling (pushing
against) each other and not moving forward or backward. (Balanced
force)
A group of people playing tug of war with one side pulls the other side
forward. (Unbalance force)
**Be able to give an example of motion and the force causing it: describe the
motion (straight lines, curved, or vibrate), identify the force that causes the
motion
Example: Basketballs bounce up and down and sometimes fly through the
air in a curved path.
I provide the force for dribbling, passing, or shooting.
Example: A cell phone vibrates back and forth when it rings. A small
device inside it shakes, providing the force to make the whole phone
vibrate.
**Be able to identify the difference between mass and weight.
**Be able to identify the measurement of force (Newtons) and the tool used to
measure force (Spring Scale)