Science - Chapter 12

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