Newton's 1st Law
What does Newton's First Law say about an object at rest?
It will stay at rest unless a net/unbalanced force acts on it.
What does the equation F = ma mean? (Write out what it says in words.)
What does the equation F = ma mean?
What is Newton’s Third Law in words?
For every action, there is an equal and opposite reaction.
What is the force that pulls objects toward the Earth?
Gravity or weight
What is the definition of mass?
The amount of matter in an object.
What does Newton’s First Law say about an object in motion?
It will keep moving at the same speed and in the same direction unless a net/unbalanced force acts on it.
All acceleration in the universe is caused by...
Net forces or unbalanced forces
When you push on a wall, how does the wall push back on you?
The wall pushes back with an equal force in the opposite direction.
What type of force opposes the motion of a sliding object?
Friction
What is the definition of weight?
The force of gravity acting on an object.
What do we call the tendency of objects to resist changes in motion?
Inertia.
If I'm travelling at a constant velocity, what is the net force acting on me in Newtons?
0 N
I kick a soccer ball with 40 N of force to the left. What is the magnitude and direction of the force that the soccer ball pushes back on me?
40 N to the right
If I stand on a chair and push up on the ceiling, the normal force that the ceiling pushes back on me will be in what direction?
Down
How do we measure mass? Weight?
Mass: kg ; Weight: N
If a car suddenly stops, why do you keep moving forward as a passenger?
Because your body wants to keep moving in the same way it already was due to inertia.
If you push a car and a bicycle with the same force, which one will accelerate more? Why?
Bicycle because it has less mass.
If a rocket launches into space, what is the action force, and what is the reaction force?
The action is the rocket pushing gas downward, and the reaction is the rocket being pushed upward.
If you push a book on a table and it doesn’t move, what force is stopping it?
If I sent my dog to Jupiter, where gravity is stronger, how would my dog's mass change?
It wouldn't change, since mass is the amount of matter in an object and this doesn't depend on location.
Normally, when we roll things on the ground they slow down until they stop eventually. Does this disprove Newton's First Law? (Yes or no, and why?)
No, since the object experiences unbalanced forces due to air resistance and friction, causing it to change its motion.
If the mass of an object is doubled but the force stays the same, what happens to the acceleration?
The acceleration will be halved.
Why does a fish move in the water by pushing against the water with its fins?
The fish pushes the water backward (action), and the reaction is the fish moving forward.
A baseball is thrown through the air. Student A says that there is an applied force on the baseball the entire time it is in the air, keeping it going. Student B says that the applied force is only present when the baseball is being thrown. Who is right?
Student B
An object has a weight of 50 N on Earth. What is its mass? Use g = 10 m/s/s for easier math.
5 kg