Newton's First Law
What does the first law tell us about an object at rest or in motion?
It will stay at rest or in motion unless acted on by an outside force
What is another name for Newton's First Law?
The Law of Inertia
What is the equation to calculate force?
F = ma
Force = mass * acceleration
What does Newton's Third Law tell us?
For every action there is an equal and opposite reaction
What is the equation to calculate momentum?
p = mv
momentum = mass * velocity
If an object is moving at a constant speed, are the forces acting on it balanced or unbalanced?
Balanced (Net Force = 0)
What do we know about the forces acting on an object if the object is accelerating?
That the forces are unbalanced
What is the most common name for the following unit?
kg * (m/s2)
What happens when you push against a wall?
Who discovered the law of universal gravitation?
Isaac Newton
If a car suddenly stops, why do passengers feel like they are pushed forward?
Because of inertia (their bodies want to resist the change in motion)
An object sliding across the floor comes to a stop. What is the primary force slowing it down?
Friction
If you apply the same force to two objects, one with a small mass and one with a large mass, which will accelerate more?
The object with the small mass
Why, if gravity is always pulling you down, are you able to stand at rest on the ground?
Because you are pushing the ground down and it is pushing you up in return. The force is equal and opposite to the force from gravity making your forces balanced.
What does the law of conservation of momentum tell us?
That momentum cannot be created or destroyed. It can only be transferred.
What is the force that acts against an object traveling through the air?
Air Resistance (Drag)
What do we call the tendency of an object to resist change to its motion?
Inertia
What is the force required to accelerate a 20 kg object at a rate of 10 m/s2?
200 N
F = (20 kg)*(10 m/s2)
If you push a cart with 100 N of force, what force does the cart exert against you?
100 N of force in the opposite direction
What does the law of universal gravitation tell us?
That every object exerts a gravitation pull on every other object
Why is the terminal velocity the maximum speed of a falling object?
The forces become balanced (net force = 0) between air resistance and gravity preventing the object from continuing to accelerate.
What kind of friction must be overcome to begin moving an object that is at rest?
Static Friction
A 5 kg object experiences a force of 20 N. What is the acceleration of the object?
4 m/s2
a = F/m = (20 N)/(5 kg)
Why do swimmers commonly push off from the wall?
Because by pushing against the wall, it also pushes against them which allows them to accelerate quicker.
What is the velocity of a 50 kg object travelling with a momentum of 400 kg * m/s?
8 m/s
v = p/m = (400 kg * m/s)/(50 kg)