Ch. 13Lesson 3
What are Newton’s laws of motion?
net force• combination of all forces acting
on an object• determines whether an object will
start moving, stop moving, or change direction
equilibrium• state when in which all forces acting on an object are in balance
Newton’s laws of motion
Sir Isaac Newton
• objects at rest tend to remain at rest & objects in motion tend to stay in motion unless a net force acts on it
1st law of motion
inertia• tendency of an
object to resist any change in motion
examples of inertia1. quarter on elbow trick
(stationary object)
2. passenger in moving car moving forward when car stops (remain in motion)
passenger & luggage in moving car moving forward when car stops
(remain in motion)
2nd law of motion
•motion of an object changes only when some force acts on the object
acceleration•rate @ which velocity of an object changes over time
• A force must be applied to an object to make it start moving, stop moving, speed up, slow down, or change direction.
3rd law of motion• For every action force
there is an equal & opposite reaction force.
• Forces (action force & reaction force) always occur in pairs
2nd law of motion
•motion of an object changes only when some force acts on the object
• objects at rest tend to remain at rest & objects in motion tend to stay in motion unless a net force acts on it
1st law of motion
3rd law of motion• For every action force
there is an equal & opposite reaction force.
• Forces (action force & reaction force) always occur in pairs
1st law of motion
• inertia= tendency of an object to resist any change in motion
1st law of motion
2nd law of motion•Acceleration-rate @ which velocity of an object changes over time