Which is not a force: friction, momentum, gravity, weight
momentum
What causes projectile motion: initial forward velocity, initial forward velocity and gravity, mass and acceleration, vertical velocity
initial forward velocity and gravity
A change in which of the following affects the weight of an object: momentum, velocity, acceleration due to gravity, friction
acceleration due to gravity
Which represents Newton's second law: v = d/t; F = mv; a = F/m; F = 0
a = F/m
Momentum depends upon: force only, velocity and friction, weight and mass, mass and velocity
mass and velocity
For every action force there is a: equal and opposite reaction force, friction force, net force, unbalanced force
equal and opposite reaction force
Which of the following is associated with static cling: centripetal force, weak nuclear force, the tides, gravitational force
weak nuclear force
What are forces measured in?
Newtons
You push an object across a suface. What force opposes your push?
friction
What force is responsible for the repulsion between two positively charged particles?
electric force
What is the weakest of the universal forces?
gravity
Which universal force acts over the longest distance?
gravitational force
What is a force?
a push or pull that acts on an object
If the forces on an object cancel out, they are called?
zero net forces
Three forces act on a wooden crate that is initially at rest, what is the net force acting on the crate?
zero net force
Three forces act on a wooden crate that is initially at rest, what is the resulting motion of the crate?
No movement
What is centripetal force?
a force that constantly changes the direction of an object to make it move in a circle
What particles do weak and strong nuclear forces act on?
neutrons and protrons
What happens to an object when an unbalanced force acts on it?
The object speeds up, slows down, or changes direction
When a tennis player bounces a tennis ball off a wall, which of Newton's laws are they making use of?
Newton's second law
Consider two rocks with masses of 1kg and 10kg. How does their inertias compare?
The heavier one has a greater inertia.
Why don't action-reaction forces cancel each other?
They don't act on the same object
What are two ways you can change the acceleration of an object?
You can change its force or its mass.
Only two universal forces can attract and repel. What are they?
electric forces and magnetic forces
The SI unit of force is the?
Newton
1 N =
1 kg m/s squared
What kind of friction occurs when a fish swims through water?
sliding
As you push a cereal box across a tabletop, describe the sliding friction acting on the cereal box
acts in the direction opposite of the motion
The forces on a falling leaf are:
gravity and air resistance
An open parachute increases air resistance of a falling sky diver by?
increasing the surface area
The property of matter that resists changes in motion is called?
inertia
The acceleration of an object equals the net force acting on the object divided by the object's?
mass
Your weight equals?
mass times the acceleration due to gravity
The product of an object's mass and velocity is its?
momentum
Which of the following is a weak nuclear force: lightning, nuclear decay, ocean tides, static cling
nuclear decay
The gravitationl force between two objects increases as mass?
decreases
The path of motion of a thrown javelin is an example of?
projectile motion