Module Two Test Review Science

What motion was Galileo watching when he became intrigued with the pendulum?

a chandelier swinging

The tendency of an object to resist a change in its motion is called ________.

inertia

Centripetal force is an ____________ force.

inward

Astronauts on the International Space Station (ISS) float because they are weightless even though their _______ is the same as when they are on earth.

mass

The amount of matter in an object is called the ____.

mass

In what kind of terms did Newton express his laws?

mechanical

Adding a lubricant Making surfaces smoother - one way to do this would be by polishing the surfaces Using wheels to move objects

Ways to Reduce Friction

Whether something sinks or floats isn't determined by the weight it is determined by density, and while a cruise ship is incredibly heavy it's not incredibly dense.

What keeps a cruise ship that weighs over 50,000 tons from sinking in the ocean?

What would be considered a demonstration of static friction?

When two surfaces are pressing together but are not moving

Which of the following is correct about a car that rounds a curve while maintaining a constant speed?

With constant speed, there is still be a net force that is directed inward (relative to the curve) on the car.

Newton's First Law Of Motion states that an object at motion will remain in motion and an object at rest will remain at rest unless acted on by an outside force. When you are in a moving car, you are also an object in motion, and you're a separate object from the car. This means that if your car were to come to a very abrupt stop you would go flying through the windshield because only the car was acted on by an outside force. Luckily, cars have seatbelts that act as an outside force to prevent you from continuing to move forward when your vehicle comes to a stop. So it's important to take advantage of your seatbelt and remain safe.

Write a paragraph of no less than five sentences explaining how Newton's First Law of Motion supports people's need to wear seat belts when riding in a moving car. Remember to use proper grammar and mechanics when writing your paragraph.

The larger an object is the _____ attraction it exerts on other objects.

greater

A(n) ______ is what scientists call a proposed answer to a problem based on known facts that are used as a basis for further experimentation.

hypothesis

Salt dissolved in a liquid makes it ________ dense.

more

An object in ____ tends to stay in _____, and an object at rest tends to stay at rest unless the object is acted upon by an outside ____.

motion, motion, force

When an object neither sinks or floats it has ___________ buoyancy.

neutral

Newton's 3rd law of motion states that for every action there is an equal but ________ reaction.

opposite

We know that every object exerts an attraction on every other object and the greater the mass of the object the _______ the attraction.

stronger

Effect of doubling the length of the string of a pendulum have on its swing

swing is slowed down

What effect does doubling the length of the string of a pendulum have on its swing?

the swing is slowed down

What effect does doubling the mass of the bob on the end of a pendulum have on its swing?

there is no effect

The word centripetal means ___.

toward the center

Another way of stating Archimedes' Principle is the ______ of the displaced liquid equals the ______ of the floating object.

weight

What standard measure does this represent? 1 cm3 of water

1 gram

While sitting on the couch, I am pushing down on it and it is pushing up on me. Which of Newton's laws of motion is this demonstrating?

3rd Law of Motion

How much force is needed to accelerate a 38 kg block at 1.2 m/s2?

45.6N

The ______ of an object is dependent upon the _____ acting on the object and the ____ of the object.

Acceleration, force, mass

What was Galileo's conclusion after thinking about this problem?

Both balls would hit the ground at the same time.

The term _________ refers to the upward-directed force that a fluid (either a liquid or a gas) exerts on an object that is partially or completely immersed in the fluid.

Buoyant Force

_________force is the force perpendicular to the velocity of an object moving along a curved path. The force always acts inward as the velocity of the object is directed perpendicular to the circle. The centripetal force is directed toward the center of the curvature path.

Centripetal

A ball rolls across the floor and it does not stop until it hits the wall; which of Newton's Laws of Motion does this demonstrate?

First Law of Motion

Objects denser than water will _______ and objects less dense than water will________.

Float, sink

__________ is a force that opposes the motion of two objects or makes it difficult for them to move past each other.

Friction

What scientist was the first to experiment with pendulums?

Galileo

Fish achieve neutral buoyancy through an air filled sac called the swim bladder.The swim bladder controls the fish's buoyancy by varying the gas (air) pressure inside the fish's body to allow it to sink or rise in the water.

How do fish maintain neutral buoyancy?

If you apply a little more force, the object "breaks free" and slides, although you still need to apply force to keep the object sliding.

Kinetic Friction

This one change in a pendulum changes the time to complete a swing

Length

When you are standing inside a subway train and the train suddenly stops, but your body continues to move forward.

Newton's 1st Law

when Jane drives to work, she always places her purse on the passenger's seat. by the time she gets to work her purse has fallen of the seat.

Newton's 1st Law

Centripetal force demonstrates which of Newton's laws of motion?

Newton's 1st Law Of Motion

Which law is it? You hit a ping pong ball and a tennis ball with a tennis racket. The ping pong ball will travel farther.

Newton's 2nd Law

a smaller cannon ball leaves a cannon much faster than a larger cannon ball fired at the same time

Newton's 2nd Law

when you give your friend a lift on your bike you have to pedal harder and faster to keep the same speed (acceleration) as you had when you were your bike alone.

Newton's 2nd Law

The reason your shoulder is so sore from practicing sharpshooting with your rifle is due to Newton's ____________ law.

Newton's 3rd Law

a climber pulls down on a rope causing his body to lift upward and rise along the rope.

Newton's 3rd Law

two bumper cars collide into each other and each car jolts backwards.

Newton's 3rd Law

Effect of doubling the mass of the bob on the end of a pendulum have on its swing

No effect

Give two ways friction can be reduced.

One way friction can be reduced is by using a lubricant, a substance used to reduce friction. A secondary way friction can be reduced is by minimizing the amount of contact between two opposing surfaces by using wheels or runners.

In a paragraph of no less than three sentences, explain why pulling a suitcase with rollers is easier than dragging one across the floor. Remember to use proper grammar and mechanics when writing your paragraph.

Pulling a suitcase with rollers is easier than dragging one across the floor because the one with rollers creates less friction. A suitcase with rollers allows the suitcase to roll against the floor, and because there is less friction the suitcase requires less force. You have to put less strength into something that requires less force to move.

If an object has a higher density than the fluid it is in (fluid can mean liquid or gas), it will sink. If it has a lower density, it will float.

Sinking vs Floating

Static Friction. If you try to slide two objects past each other, a small amount of force will result in no motion. The force of friction is greater than the applied force.

Static Friction

According to the lesson on Centripetal Force, which sport can use the study of this force to help you excel?

Studying centripetal force can help golfers improve at their sport.

Imagine you have a ball tied to the end of a string. You hold the other end of the string and swing it around. Suppose the string breaks, what direction will the ball travel?

The only reason the ball is traveling around in a circular shape is because of the string, so if the string were to fail the ball would travel in a straight line tangent to the circle the ball was traveling in.

For every action, there is an equal but opposite reaction is the _______.

Third Law of Motion

The rate of change of velocity is called _______.

acceleration

Every ____ has an equal and opposite ______.

action, reaction

What do we call a floating object anchored in water to mark something?

buoy

The _______________ is the point in an object where there is as much weight on one side as on the other side. This is also called the center of balance.

center of gravity

Without the force of gravity, an object pushed into space would ______.

continue to move forward

You can increase the speed of a pendulum by ______ of the string or cord.

decreasing the length

The state of motion is a speed and a _____.

direction

What do scientists call the distance to the right or left of the pendulum's normal hanging position?

displacement

Which of these is an example of centripetal force?

electrons around a nucleus

Galileo concluded that planets that are closer to the sun orbit ________ than those further out.

faster

According to the Law of Inertia, an object at rest will stay (remain) at rest unless acted upon by a(n) ____.

force

A force that opposes motion between two surfaces that are in contact with each other is called ______.

friction

Liquids and _________ are considered to be fluids.

gases

What force keeps the planets in their orbit?

gravity

What force pulls an object flying through the air to the ground?

gravity