Download Name: Period: _____ Newton`s Laws of Motion Newton`s 1st Law

Name: ___________________________
Period: _____
Newton’s Laws of Motion
Newton’s 1st Law:
Objects in motion, will remain in motion, and objects at rest will remain at rest
until acted on by an outside force.
Inertia: The tendency of an object to resist a change
in its motion.
 An unbalanced force that acts on an object in motion is called friction
Types of friction

Sliding friction ex: ice skating

Rolling friction ex: bowling

Fluid friction (air or liquid): ex: air or water resistance (comet entering our atmosphere or leaf falling
from tree)

Static friction ex: initial friction when moving an object
 Mass is the amount of matter in an object.
 The more mass an object has the more inertia the object has. Bigger objects are harder to start & stop.
Newton’s 2nd Law: Force = mass X acceleration
F=M*A
Force = a push or a pull (N)
Mass = the amount of matter an object has (kg)
Acceleration = a change in speed (m/s2)
 The more force placed on an object, the more it will accelerate (change its motion)
 The more mass (or INERTIA) an object has, the more force it takes to accelerate the object
Solve:
A net force of 15 N is exerted on an encyclopedia to cause it to accelerate at a
rate of 5 m/s2. Determine the mass of the encyclopedia.
F = 15N
M=
𝑭
𝑨
=
𝟏𝟓 𝑵
𝟓 𝒎/𝒔𝟐
= 3 kg
M=?
A = 5 m/s2
You throw a ball to a friend. If the ball has a mass of 0.15kg and it accelerates at 20m/s2, what force did
you exert on the ball?
M = 0.15 kg
F = m*a = 0.15 * 20 = 3 N
A = 20 m/s2
You throw a 0.5 kg ball with a force of 10N. What is the ball's acceleration?
F = 10 N
A=
𝑭
𝒎
=
𝟏𝟎 𝑵
𝟎.𝟓 𝒌𝒈
= 20 m/s2
M = 0.5 kg
A=?
Newton’s 3rd Law:
For every action, there is an equal and opposite reaction.
When you sit in your chair, your body exerts a downward force on the chair and the chair exerts an upward
force on your body. These two forces are called action and reaction forces.
The baseball forces the bat to the left (an action); the bat forces the ball to the right
(the reaction).
Consider the motion of a car on the way to school. A car is equipped with
wheels which spin backwards. As the wheels spin backwards, they grip the
road and push the road backwards.
Which Law is it?
Amy weighs 78 pounds and her dad weighs 187 pounds. They are roller skating. Amy challenges her dad to a
race. They stand poised at the starting line. Her dad yells, "Go!"
Newton’s 1st Law
Newton’s 2nd Law
Newton’s 3rd Law
Jack is carrying a cup of water. He doesn't see a wrinkle in the floor rug and he trips. Jack manages not to fall
or drop the cup, but the water sloshes over the side of the cup and onto the floor.
Newton’s 1st Law
Newton’s 2nd Law
Newton’s 3rd Law
A skateboarder uses his foot to push off on the ground, the skateboard then moves forward.
Newton’s 1st Law
Newton’s 2nd Law
Newton’s 3rd Law