Science Chapter 2: Forces

Newton's first law of motion states that an object will not experience a change in motion unless acted upon by a \______________ force

balanced

To increase acceleration of an object, you reduce its \______ or increase the applied force

mass

Newton's third law of motion states that if one object exerts a force on another object, then the second object exerts a force of equal strength in the \____________ direction.

opposite

Resistance to change in motion

inertia

Action and reaction forces acting in opposite directions (do, do not) cancel out because they act on different objects.

do not

If you lean against a wall, the wall pushes back on you with a(n) (weaker, stronger, equal) force

equal

Newton's second law of motion states that an object's acceleration depends on its \__________ and on the net force acting on it.

mass

Acceleration is measured in \_____________________

meters per second squared

Force is measured in a unit called the \_____________

Newton (N)

The smaller the mass of an object, the \______________ its inertia

smaller

When you swim in a pool, \______________ friction occurs

fluid

When you rub your palms together, \_________ friction occurs

sliding

When you skateboard on a ramp, \_____________ friction occurs

rolling

When you push a desk that doesn't move, \_______ friction occurs

static

The \______________________________ states that forces of gravity act between all objects in the universe that have mass

Law of Universal Gravitation

As distance increases, gravitational force \____________

decreases

When you stand on a bathroom scale, it displays the \____________________ that earth is exerting on you

gravitational force

Friction acts in a direction \_____________ to the direction of the object's motion

opposite

When the irregularities of one surface come into contact with those of another surface, \___________ occurs

friction

The applied force required to push something across a surface \____________ as friction increases

increases

What is the formula used to calculate momentum?

Momentum \= Mass x Velocity

In what situation does the Law of Conservation of Momentum apply?

the absence of outside forces

The total momentum of any group of objects \____________________ unless outside forces act on the object

remains the same

If outside forces such as friction are negligible, when two objects of the same mass collide and do not stick together, the objects \____________ velocities

exchange

Newton's "quantity of motion" is called \___________

momentum

The less momentum an object has, the \____________ it is to stop

easier

Momentum, like velocity, is described by \_____________

strength

The momentum of a 1000-kg vehicle traveling at a velocity of 25 m/s is \____________

2500kg*m/s

A push or pull exerted on an object

force

A unit of measurement that equals the force required to accelerate a kilogram of mass at a meter per second, an SI Unit

Newton (N)

The overall force on an object when all the individual forces acting on it are added together

net force

A force is described by its \___________ and by the \___________ in which it acts

force and direction

The direction and strength of a force can be represented by an \__________ pointing in the same direction

arrow

The length of an arrow tells you the \__________ of the force

strength

The net force determines if and how an object will \__________________

accelerate

A \___________ net force causes a change in the object's motion

non-zero

Think of all forces that act to the \__________ as positive and all forces to the left as \_____________ when calculating net force

right, negative

The motion of a falling object when the only force acting on it is gravity

free fall

Any object that orbits around another object in space

Satellite

A force that causes objects to move in a circle

Centripetal Force

When something falls on Earth, there is \_______________ from the air around it

fluid friction

If an object falls for long enough, increased air friction will reduce its \_____________ to zero

acceleration

Near the surface of the earth, the acceleration due to gravity is \______________

9.8m/s^2

Satellites in orbit around Earth continually \_________________, but because Earth is curved, they travel around it

fall toward it

Once a satellite has entered a stable orbit, it does not need fuel. It continues to move ahead due to its \____________

inertia

An object traveling in a circle is accelerating because it is \___________________

constantly changing direction

The word "centripetal" means \_________________

center-seeking

If you could turn off a centripetal force, interia would cause the object to fly off in a \_______________

straight line