Net force
What is net force?
The overall force acting on an object after all forces are combined.
What does the length of an arrow in a free body diagram represent?
The magnitude (strength) of the force
What is the formula for Newton’s Second Law?
Force = Mass × Acceleration (F = m × a)
What does Newton’s Third Law state?
For every action, there is an equal and opposite reaction.
In a force pair, which force is the one that starts the interaction?
The action force
What do you do with forces going in the same direction?
Add them together.
What does the direction of an arrow in a free body diagram show?
The direction of the force
What happens when you push harder on an object?
It accelerates more
What do we call the two forces involved in Newton’s Third Law?
A force pair
What is the force that responds to the action force?
The reaction force
What do you do with forces going in opposite directions?
Subtract the smaller from the larger.
If three people push a piano with forces of 130N right, 150N left, and 165N right, what is the net force?
145N to the right
What is the acceleration of an 8 kg rock with a net force of 24 N?
3 m/s²
Why don’t force pairs cancel each other out?
Because they act on different objects
What causes a gun to recoil when fired?
The reaction force from the bullet being pushed forward
What is the net force when forces are balanced?
Zero
If three people push a piano with forces of 130N right, 150N left, and 165N right: Will the piano move, and in which direction?
Yes, to the right
What is the mass of a skater if a 30 N force causes an acceleration of 0.6 m/s²?
50 kg
What is the action force when you step on the floor?
Your foot pushing down on the floor
What is momentum?
The measure of how hard it is to stop a moving object
What happens to an object when forces are unbalanced?
It changes motion (accelerates, decelerates, or changes direction).
What net force is needed to accelerate a 114 kg wagon at 1.5 m/s²?
171 N
What is the reaction force when you step on the floor?
The floor pushing up on your foot
Why can force pairs change the motion of objects?
Because they act on different objects