Physical Quantities
A push or a pull.
Force, F
savg = 20 m/s
Δt = 4 s
d = ?
80 m
When the net force acting on an object is zero.
Equilibrium
The force acting on everything on Earth.
Gravity
An object's x-t graph makes this shape when it has come to a complete stop.
Horizontal line
The length of a curved path, regardless of its shape.
Distance, d
A dog walks in a straight line for 1.6 km in 200 s. What is the dog's average velocity?
8 m/s
When an object has constant velocity.
Equilibrium
The force that usually stops us from falling into the center of the Earth.
Normal force
Slope
How fast an object travels, regardless of the shape of its path.
Speed/average speed, savg
A runner completes a loop of the track out back in 180 s, which is 400 m all the way around. What is the runner's average velocity?
0 m/s
When an object has zero velocity.
At rest
The tension force is exerted by this kind of object.
Rope
An object's x-t graph makes this shape when it is moving in equilibrium.
The straight line length between an object's initial & final locations.
Displacement, Δx
A car travels 144 km with an average speed of 36 kph. How long is the car's trip?
4 hrs
The tendency for an object to "want" to keep moving.
Inertia
If an object slides along a rough surface, it feels this force.
Kinetic friction
An object's x-t graph is curved or has a corner when this happens to the object.
Feels a net force OR is not in equilibrium
The name for the type of quantities that have a magnitude & direction.
Vector
v = 3×108 m/s
Δx = 6×1010 m
Δt = ?
Δt = 200 s
The "natural" state of motion of objects in our universe.
The official name for the force exerted by objects "gripping" the ground, like feet, wheels, or stationary objects.
Static friction
When an object's direction changes, this happens for a moment.
The object is at rest.