Force
What is a force?
A push or a pull
What is friction?
The force between two surfaces that are in contact with each other
Newton's Law of Universal Gravitation states that all objects that have mass also do what?
Attract each other
What two things do you need to know in order to determine the momentum of an object?
Its mass and its speed.
What force is acting on an object in free fall in order to pull it down?
Gravity
What unit is used when measuring force?
Newtons
What kind of friction is a hockey puck being hit across the ice?
Sliding friction
According to Newton's First Law of Motion, objects at rest will stay at rest and objects in motion will stay in motion unless what happens?
They are acted on by an outside force.
What is the unit used when measuring momentum?
kg x m/s
What force is acting on an object in free fall that might slow it down?
Air resistance or drag
What two things are used to describe a force?
Strength and direction
What kind of friction is a canoe moving through water?
Fluid friction
Newton's Third Law of Motion states that for every action there is what?
An equal and opposite reaction
A red ball with a momentum of 2 kgm/s hits a blue ball with a momentum of .5 kgm/s. What will the momentum of both balls be after the collision?
The blue ball will have a momentum of 2 kgm/s while the red ball will have a momentum of .5 kgm/s.
The mass of the objects and the distance between them
If the net force on an object at rest is zero, what will happen to that object?
It will not move.
Give an example of static friction.
Answers may vary.
A boxer punches a bag with 5 Newtons of force. What is the reaction force and how strong is it?
The bag pushes back on the boxer with 5 Newtons of force.
200 kgm/s
What is an object's acceleration when in free fall?
9.8 m/s2
Name any four forces.
Gravity, friction, centripetal, drag/air resistance, magnetic force, spring force
What are the two main factors affecting friction?
The type of surface and the strength of the push or pull applied
According to Newton's Second Law, force is determined by what two things about an object?
Its mass and its acceleration.
What is the law of conservation of momentum?
Momentum cannot be created or destroyed in a collision.
What is the difference between mass and weight?