Motion Basics
Quantity that describes how fast an object is moving
Speed
Newton’s law that explains why objects resist changes in motion
Newton’s First Law
The force that pulls objects toward Earth
Gravity
Quantity calculated using mass and velocity
Momentum
Energy an object has due to motion
Kinetic energy
Quantity that includes both speed and direction
Velocity
Law that states force equals mass times acceleration
Newton’s Second Law
Approximate acceleration due to gravity near Earth
9.8 m/s²
Type of quantity momentum is
Vector
Energy an object has due to height
Gravitational potential energy
Term that describes a change in velocity over time
Acceleration
Law that explains action–reaction force pairs
Newton’s Third Law
Type of motion where gravity is the only force acting
Free fall
Collision where objects stick together
Inelastic collision
The sum of kinetic and potential energy
Mechanical energy
Motion where speed and direction do not change
Constant velocity
according to Newton’s First Law, this must be true for an object to change velocity
A net force must act on the object
At the top of its path, an upward-thrown object has this velocity
Zero
Collision in which kinetic energy is conserved
Elastic collision
What doubles when work stays the same but time is cut in half
Power
When an object slows down while moving forward, the acceleration is in this direction
Opposite the direction of motion
Law that explains why seatbelts are needed in a sudden stop
Newton’s First Law
In free fall (ignoring air resistance), heavy and light objects do this
Fall at the same rate
Quantity that is always conserved in a closed system during a collision
Momentum
What happens to kinetic energy when speed doubles
It quadruples