2nd Quarter Review

2nd Quarter Review

Go through the slides, watch the videos, answer the questions to help you review for the 2nd quarter benchmark.

Force

A Push or a Pull

Friction: Balanced & Unbalanced, Friction, Gravity

Friction

Friction is a force that opposes the motion of one object moving past another. It slows things down and stops them.

Gravity

Gravity is a pulling force that works across space. Objects do not have to touch for the force of gravity to affect them. Example, if you jump up, you are not touching the Earth, but you are pulled toward it.

Gravity & Friction

Balanced and Unbalanced Forces

We will now look at 2 types of Forces, Balanced and Unbalanced

Balanced Forces

Forces that cancel each other out when acting together on a single object. When you have Balanced Forces, there is no movement. For example, in the picture, if both sides pull with equal force, there is no movement.

Unbalanced Forces

Forces that do not cancel each other out when acting together on a single object. When you have Unbalanced Forces, you WILL have movement. For example, in the picture, one side is pulling with more force. The rope and the other side will move in the direction of the greater force.

Mass and Inertia

In the next set of slides we will look closer at Mass and Inertia and how they affect the motion of an object.

Mass

The amount of matter in an object.

Mass

We know that we get mass by determining how much matter is in an object. It's easy to say an elephant has more matter than a leaf. An elephant is way bigger. Be careful though, it's not necessarily about size. A beach ball is bigger than a bowling ball, but it has less mass because the bowling ball has more "stuff" (matter) on the inside.

Inertia

An object has the tendency to stay at rest unless acted on by a force to get it moving, or to stay moving unless acted on by a force to stop it. For example, our class Newton's cradle will just sit there until acted on by one of us to get it moving. Once moving, it will keep moving until a force (friction) starts to slow it down and stop it.

Newton's 3 Laws

We know that Newton has 3 Laws of Motion. In the next few slides we will take a look at those.

Newton's 1st Law

Newton's 1st law should sound very familiar. An object has the tendency to stay at rest unless acted on by a force to get it moving, or to stay moving unless acted on by a force to stop it. "Mr. B, that sounds just like Inertia." Exactly, they are the same thing. Sometimes Newton's 1st Law is referred to as The Law of Inertia.

Newton's 2nd Law

The second law states that the greater the mass of an object, the more force it will take to accelerate the object.

Newton's 3rd Law

The third law states that for every action, there is an equal and opposite reaction. 

Multiple Choice

In tug-of-war, both teams pull and the rope moves towards one team. What could be the cause?

• The friction is balanced.

• The forces are balanced.

• The motion is not balanced.

• The forces are unbalanced.

Multiple Choice

Which best describes the relationship between movement and friction?

• As the friction increases, the rate of movement increases.

• As the friction increases, the rate of movement decreases.

• As the friction decreases, the rate of movement decreases.

• As the friction decreases, the rate of movement is unchanged As the friction decreases, the rate of movement is unchanged

Multiple Choice

Which surface will most likely cause a rolling ball to slow down the fastest?

• Ice

• Tile

• Glass

• Grass

Multiple Choice

When rolling a ball on the ground, what force makes it come to a stop?

• Mass

• Gravity

• Friction

• Altitude

Multiple Choice

What force must a person overcome in order to push a box across the flat surface?

• friction

• gravity

• mass

• density

Multiple Choice

How does motor oil help to keep a car’s engine from getting too hot?

• by reducing friction

• by increasing magnetic attraction

• by lowering the temperature of the air under the hood

• by increasing friction by increasing friction

Multiple Choice

Which investigation will BEST test the effects of gravity on moving objects?

• pencils falling from the same height

• balloons floating upward from the same height

• a bicycle speeding up on a flat surface

• a ball slowing down on a flat surface a ball slowing down on a flat surface

Multiple Choice

Don throws a ball in the air. The ball comes back to the ground because

• the wind pushes on the ball with friction.

• the mass of Earth creates a pull of gravity on the ball.

• the Earth core pulls on the ball with a magnetic attraction

• the weight of the atmosphere pushes down on the ball. the weight of the atmosphere pushes down on the ball.

Multiple Choice

When added to smooth road surface which would create the greatest amount of friction for a car?

• Ice

• Rain

• Soap

• Sand

Multiple Choice

The rock had a tendency to stay at rest until a force acted on it, and then it had a tendency to stay in motion until a force acted on it, which is also known as ______________________.

• Inertia

• Gravity

• Mass

• Velocity

Multiple Choice

Madelynn moved the car by using a push or pull to cause it to go in motion. Mrs. Cline said she was using ______________________.

• Force

• Mass

• Newton's 1st Law

• Acceleration

Multiple Choice

Jaddan's skateboard slowed down quicker on the gravel because of a force that opposes the motion of one object moving past another (it can also stop the motion of an object), or _______________ was greater on the gravel than on the paved road.

• Friction

• Inertia

• Mass

• Velocity

Multiple Choice

The geologist measured how much matter was in the rock, or its ____________ to determine what type of rock it was.

• Mass

• Newton's 1st Law

• Friction

• Velocity

Multiple Choice

A soccer ball will stay at rest until acted on by a force. Once kicked it will stay in motion until acted on by a force. Which term best describes this?

• Newton's 1st Law

• Gravity

• Friction

• Mass

Multiple Choice

If we put a bowling ball and feathers in a room, vacuumed out the air, and dropped them from the same height, they would hit the ground simultaneously. When we drop them in a regular setting, the bowling ball hits first. Why?

• Gravity is different

• The mass changed

• When you have air, you have friction, which slowed the feathers

• Kinetic energy left the bowling ball faster

Multiple Choice

What force allows this tru...OMG IS IT GOING TO STOP???!!! OK, thank goodness. What force allows the truck to stop?

• Gravity

• Mass

• Friction

• Kinetic Energy

Multiple Choice

You can memorize an object's acceleration depends on the size and direction of the force, and the mass of the object.But, it's easier to say the more mass something has, the more force you need to move it when talking about _________________.

• Newton's 2nd Law

• Newton's 3rd Law

• Newtons

• Kinetic Energy

Multiple Choice

Also known as the law of inertia, ________________________ states that an object at rest, stays at rest and an object in

motion tends to stay in motion, in the same direction and

speed...unless acted on by a force.

• Newton's 1st Law

• Newton's 2nd Law

• Newton's 3rd Law

• Fig Newtons

Multiple Choice

Austin and Wesley were in a tug-of-war match with Markise and Brody and there was no movement because of forces that canceled each other out when acting together on a single object or as Christian called it _________________,

• Balanced Forces

• Unbalanced Forces

• Potential Energy

• Electrical Energy

Multiple Choice

When one team pulled harder than the other in tug-of-war, there was movement so Zhoe knew it was _________________________, or forces that do not cancel each other out when acting together on a single object.

• Unbalanced Forces

• Balanced Forces

• Friction

• Gravity

Multiple Choice

When one team pulled harder than the other in tug-of-war, there was movement so Zhoe knew it was _________________________, or forces that do not cancel each other out when acting together on a single object.

• Unbalanced Forces

• Balanced Forces

• Friction

• Gravity