Force and Motion

Force and Motion

Review Time!

Inertia- Newton's 1st Law

An object in motion will stay in motion, an object at rest will stay at rest UNLESS a force acts upon it.

Multiple Choice

Which is NOT an example of inertia- Newton's 1st Law.

• A book sitting on a table does not move.

• Wearing a seatbelt so you don't keep moving forward when a car stops suddenly.

• A rocket blasting off into space.

• Moon orbiting the Earth.

Force

A force is a push or a pull.

Multiple Choice

Which of the following is NOT using a force?

• a man pushing a shopping cart

• a cat sleeping on the couch

• a dog playing tug-of-war with a rope

• an eagle carrying a fish it caught

Motion

Motion is movement.

Multiple Choice

What statement correctly describes the motion of the toy car?

• It is standing still.

• It is speeding up.

• It is slowing down.

• It is moving at constant speed.

Friction

Friction is a force that slows down moving things.

Multiple Choice

A child rides a wagon down a hill. Eventually, the wagon comes to a stop. What is MOST responsible for cuasing the wagon to stop?

• Gravity acting on the wagon.

• Friction acting on the wagon.

• The mass of the wagon.

• The mass of the child.

Multiple Choice

The box would be easier to move if the surface of the ramp was smoother because there would be less...

• mass in the box.

• friction opposing the box.

• gravity pulling on the box.

• distance to push the box.

Direction

Direction is the course torwards which something moves.

Multiple Choice

A ball is moving in a certain direction. What would happen to the ball if a greater force was applied on the ball along its direction of motion?

• The speed of the ball would decrease.

• The ball will stop instantly.

• The speed of the ball would increase.

• The ball will change direction.

Gravity

Gravity is the force that pulls things towards the center of the Earth. Gravity also pulls things towards each other.

Multiple Choice

Which phenomenon is caused by the same force that causes objects to fall toward the surface of Earth?

• Sunlight travels to the Earth.

• The moon orbits Earth

• The tails of comets point away from the sun.

• A compass needle points to the North Pole of Earth.

Multiple Choice

A pencil falls off a desk. What moves the pencil toward the floor?

• mass

• friction

• gravity

• speed

Newton's Second Law

Force equals mass times acceleration (F=MxA)

Multiple Choice

Four boxes are lifted straight up from the ground to a shelf. Each box has a different mass, as shown in the table. Which box requires the SMALLEST force to lift it off the ground?

• L- 4.5 kg

• M- 10 kg

• N- 3.5 kg

• O- 5 kg

Multiple Choice

The two carts shown have different combinations of Force and Mass. Which cart reaches at 5 m/s first?

Multiple Choice

The two carts shown below have different combinations of Force and Mass. Which cart reaches at 5 m/s first?

Multiple Select

A student stacks books on a skateboard and pushes it down a hall. Click on each change the student could make that would result in the skateboard reaching the end of the hall faster.

• Push the skateboard with less force.

• Push the skateboard with greater force.

• Remove some of the books.

• Stand the books upright.

• Replace the books with heavier objects.

Speed

Speed is the rate of movement. To calculate speed, you need to know the time it takes to move a certain distance (S=D/T).

Multiple Select

Scientists use electronic devices to collect data about birds during a migration. These data are shared on the Internet for anyone to view. A student analyzes the data and concludes that one bird flies at a speed of 20 meters per second during a portion of its migration. Select the TWO types of data that the student needed to form this conclusion.

• the time intervel between data points

• the bird's location

• the direction of the wind

• the bird's wing length

• the direction the bird flies

Multiple Choice

An ant crawls up a table leg from point X to the top of the table to point Y. Then it crawls across the tabletop to point Z. The graph lines show that each square measures 50 centimeters (cm) in length. It took the ant 2 minutes (min) to walk from point X, all the way to point Z. What was the average speed of the ant?

• 4 cm per min

• 25 cm per min

• 100 cm per min

• 200 cm per min

Multiple Choice

An Amazon truck makes a trip from Cleveland to Creston. The truck departs from Cleveland at 4:00 p.m. and arrives at Creston at 6:00 p.m. The truck travels at a distance of 120 miles. What is the average speed of the truck the entire journey?

• 20 mph

• 30 mph

• 60 mph

• 65 mph

Mass

Mass is the amount of matter in something. Mass is not the same thing as weight.

Multiple Choice

Four toy cars, each with a different mass, are moving at the same speed. Which toy car would require the MOST force to stop its motion?

• Toy car with a mass of 15 kg

• Toy car with a mass of 20 kg

• Toy car with a mass of 25 kg

• Toy car with a mass of 30 kg

Multiple Choice

Joseph pushes two blocks with the same amount of force. One block has more mass than the other block. Which of the following is correct?

• The block with more mass will not move as far as the other block.

• The block with more mass will move farther than the other block.

• There is no relationship among force, mass, and distance.

• An object with more mass will need less force to move it.

Acceleration

Acceleration is the increase in the rate of speed.

Multiple Choice

A person with a mass of 75 kg is accelerated to 3 m/s. How much force was applied to him?

• 25 Newtons

• 225 Newtons

• 78 Newtons

• 675 Newtons

Multiple Select

Students set up an experiment with different small objects and a tabletop covered in ice so that friction is not a factor. The students give each object a short push to start it moving across the top of the table and record the resulting speed of each oject. Select the TWO factors that have the greatest effect on the speed of the objects.

• force of the push

• shape of the object

• length of the tabletop

• mass of the object

• time the object was slid

Newton's Third Law

For every action there is an equal and opposite reaction.

Multiple Choice

Which of the following is an example of Newton's 3rd Law?

• Earth orbiting the sun.

• Using an oar to row a boat.

• Laying on the couch.

• Watching television.

Poll

How many of you are ready for tomorrow's test over Force and Motion?

• I am ready, but I will still study.

• I have more studying to do. I'm not quite ready yet.

• I am not ready at all...I have a lot of studying to do!