First Law
What does Newton’s 1st Law state?
An object stays at rest or moves at constant speed in a straight line unless acted on by an unbalanced force.
Formula for Newton’s 2nd Law?
F = ma.
State Newton’s 3rd Law.
For every action, there is an equal and opposite reaction.
Which law explains why it’s hard to push a heavy couch?
Newton’s 2nd Law.
Balanced forces cause acceleration. True or False?
False.
Why do passengers lurch forward when a car suddenly stops?
Their bodies resist the change in motion (inertia).
Mass = 10 kg, acceleration = 2 m/s². What is the force?
20 N.
What force makes a balloon rocket move forward?
The air pushing backward, reaction pushes balloon forward.
Why do rockets move upward?
Gases push down, rocket pushed up (3rd Law).
What is the net force if 20 N right and 10 N left?
10 N right.
True/False: Inertia is stronger in heavier objects.
True
A truck and a car are pushed with equal force. Which accelerates more, and why?
The car, because it has less mass.
When you jump off a skateboard, what happens to the skateboard?
It rolls backwards (reaction).
A ball keeps rolling on smooth ice until stopped. Which law?
Newton’s 1st Law.
Velocity is different from speed because it includes what?
Direction.
Which law explains why seatbelts are necessary?
Newton’s 1st Law.
If you double the force on an object, what happens to its acceleration?
It doubles.
A swimmer pushes water back. What force moves the swimmer forward?
Water pushes forward.
A car with larger mass needs more force to accelerate. Which law?
2nd Law.
What happens to an object if no force acts on it?
It keeps moving at constant speed (or stays still).
A soccer ball won’t move until it’s kicked. What concept explains this?
Inertia (First Law).
A 50 kg student runs with an acceleration of 3 m/s². What force do they apply?
150 N.
A rocket is launched in space where there is no air. If there’s nothing to “push against,” why does it still move forward?
Because gases are expelled backward, and the rocket is pushed forward by the equal and opposite reaction force.
When you punch a wall and your hand hurts, which law is it?
3rd Law.
A 2000 kg truck accelerates at 4 m/s². What is the net force?
8000 N.