# Motion & Forces Practice Quiz 1

gravel
sand
the grass
a sidewalk

### The force that always acts opposite to the direction of the motion of an object is called_____

gravity
inertia
friction
none of these

### According to Newton's 3rd law, forces always occur in ____ pairs.

equal but complementary
equal but opposite
unequal but opposite
unequal but complementary

### Neweton first described gravity while watching _____

smoke rise
a car accelerate
someone walking
an apple falling

### You would NOT use _____ to find the acceleration of an object.

initial speed
final speed
weight
time

first
second
third
primary

Friction
Mass
Gravity
Velocity

### To calculate average speed, you would use _____

weight and distance
distance and time
acceleration
weight and time

### ______ is used to describe an object slowing down because of decreasing speed.

Acceleration
Average speed
Negative acceleration
Inertia

### An object that has a(n) _____ will acceleration in the direction of the force.

normal force
net force
frictional force
speed

Friction
Deceleration
Speed
Inertia

Force
Speed
Motion
Acceleration

All of these
Friction
Gravity
Mass

### Stepping on a wagon and watching the wagon move away from you is an example of Newton's _____ law.

first
third
second
gravitational