Types of Forces
What type of force is applied when you hit the keys on a keyboard?
Applied force
What made the ball move when you rolled it across the floor?
applied force
Who developed the Law of Universal Gravitation?
Sir Isaac Newton
What type of friction prevents an object from starting to move?
static friction
What does Newton’s First Law say about an object at rest or in motion?
It will stay at rest or in motion unless acted on by an unbalanced force.
What force resists motion when you try to slide a box across the floor?
friction
What made the ball stop after you let go of it?
frictional force
What two factors affect the strength of gravitational force?
Mass and distance
What type of friction slows down a moving object?
Sliding friction
What must happen for an object’s motion to change?
An unbalanced force must act on it.
What kind of contact force slows down a parachute as it falls?
air resistance
What force made the ball fall back into your hand after you tossed it?
gravity
What is the difference between mass and weight?
Mass is the amount of matter in an object and does not change; weight is the gravitational force on an object and can change depending on location.
What type of friction occurs between an object and a fluid like air or water?
fluid friction
What is the tendency of an object to resist changes in motion called?
inertia
Why do you lurch forward when a car stops suddenly?
Because of inertia—your body wants to keep moving.
Why do satellites stay in orbit around Earth?
Because of inertia and gravity working together.