PHYSICAL SCIENCE - Chapter 2 Test

What is the acceleration for anything falling?

-9.81 m/s^2

The more inertia you have the harder it is to ______.

Accelerate

_______ ____ describes speed of motion when speed is changing.

Average speed

Plates move so slowly that their speeds are given in units of ________ per year

Centimeters

An important part of describing the motion of an object is to describe how far it has moved, which is _______.

Distance

What is the equation for speed?

Distance (in meters) / time (in seconds)

The motion of an object over a period of time can be shown on a ______-____ graph.

Distance-time

True or false. Force always changed velocity.

False

What is the formula for change?

Final - initial

After a reference point is chosen, a _____ of reference can be created.

Frame

Where is time plotted on the graph? Distance?

Horizontal axis ; vertical axis

What is the SI unit of length or distance?

Meter

What are Isaac Newton's rules called?

Newton's laws of motion

Every ____,_____, _____, or _____ results in a force being applied to an object.

Push ; pull ; stretch ; bend

Force

Push or pull

Any change over time is called a ____.

Rate

What is a vector?

Something that has magnitude and direction

True or false. A force can cause the motion of an object to change.

True

True or false. Velocity depends on direction as well as speed.

True

True or false. You don't always need to see some- thing move to know that motion has taken place.

True

From home, you walk 6 blocks east and then walk 4 blocks west. Your distance from home is: a. 2 blocks. b. 4 blocks. c. 6 blocks. d. 10 blocks.

a. 2 blocks.

Which of the following statements gives the best definition of position? a. It is a variable that gives location relative to an origin. b. It is the distance with a value of zero. c. It is the distance an object travels divided by the time it takes. d. It is the distance traveled.

a. It is a variable that gives location relative to an origin.

Variables like velocity and acceleration that have both size and direction are called: a. vectors. b. dependent. c. axes. d. independent

a. vectors

When the velocity of an object changes, the object is _________.

accelerating

The rate of change in the velocity of an object is called ____________________.

acceleration

What is Newton's first law of motion (law of inertia)?

an object moving at a constant velocity keeps moving at that velocity unless an unbalanced net force acts on it

Describe the difference between a positive and a negative acceleration

an object with a positive acceleration is speeding up and an object with a negative acceleration is slowing down

The total distance traveled divided by the total time of a trip is called ____________________ speed.

average

What is the speed of a jet plane that travels 3,000 meters in 10 seconds? a. 30 m/s b. 300 m/s c. 3,000 m/s d. 30,000 m/s

b. 300 m/s

Which of the following is a projectile? a. An airplane flying at 30,000 feet. b. A baseball hit by Chipper Jones. c. A soccer ball rolling across a field. d. A book sliding across a desk.

b. A baseball hit by Chipper Jones.

Speed that does not change is called: a. average speed. b. constant speed. c. instant speed. d. minimum speed.

b. constant speed.

The slope of a position vs. time graph is equal to: a. distance. b. speed. c. acceleration. d. area.

b. speed

If an automobile travels at 30. m/s for 2 minutes, how far has the car traveled? a. 60. m b. 1,800 m c. 3,600 m d. 216,000 m

c. 3,600 m

On a graph, all of the following directions are normally considered to be positive EXCEPT: a. North. b. East. c. Left. d. Up.

c. Left.

A racecar rounds a curve on the track at a constant speed of 180 mph. Is the car accelerating? a. No, its mass is constant. b. Yes, its speed is changing. c. Yes, its direction is changing. d. No, its speed is constant.

c. Yes, its direction is changing.

A cart is rolling down a ramp. If the angle of the ramp is increased to make the ramp steeper, the cart will: a. have less acceleration. b. have the same acceleration. c. have greater acceleration. d. move at a constant velocity.

c. have greater acceleration.

When constructing a graph, the x-axis is most closely related to: a. the dependent variable. b. the vertical axis. c. the independent variable. d. the slope.

c. the independent variable.

If large changes in the independent variable cause small changes in the dependent variable: a. the relationship is strong. b. the relationship is inverse. c. the relationship is weak. d. there is no relationship between variables.

c. the relationship is weak.

Speed that stays the same is called ____________________ speed.

constant

What is a frame of reference?

coor- dinate system in which the position of the objects is measured

A plane flies 200 km West and then flies 300 km South. Its new position is: a. +200km, +300km b. +300km, -200km c. -200km, +300km d. -200km, -300km

d. -200km, -300km

A rocket sled accelerates from 10 m/s to 50 m/s in 2 seconds. What is the acceleration of the sled? a. 10 m/s2 b. 25 m/s2 c. 40 m/s2 d. 20 m/s2

d. 20 m/s2

In 1/2 hour, a bicyclist traveled 20 kilometers. What was the bicyclist's average speed? a. 60 km b. 10 km/h c. 40 km d. 40 km/h

d. 40 km/h

A graph can be described as: a. a mathematical diagram. b. a scientific model. c. a way to show relationships between variables. d. All of the above

d. All of the above

Speed is: a. calculated by dividing the distance traveled by the time taken. b. zero for objects at rest. c. a measure of how quickly an object gets from one place to another. d. All of the above

d. All of the above

True or false. There can not be negative acceleration.

false

True or false. A steeper line on position vs. time graph means a slower speed.

false, faster

True or false. Speed is a variable that tells you how fast something is going and in what direction.

false, velocity

What is the equation for the change in velocity?

final velocity - initial velocity

What is the equation for acceleration?

final velocity - initial velocity (in meters per second) / time (in seconds)

Balanced forces

forces on an object that are equal in size and opposite in direction

An object falling only under the force of gravity is said to be in ____________________.

free fall

In an experiment, the variable that causes change in another variable is called the ____________________ variable.

independent

What are the units for acceleration?

m/s^2

What type of acceleration would best describe the motion of a motorcycle slowing down?

negative accerleration

What type of acceleration would best describe the motion of a car traveling on a highway at 60 mph using cruise control?

no acceleration

What type of acceleration would best describe the motion of a truck parked at a rest area?

no acceleration

Inertia

object's resistance to change in motion

The place where a position has a value of zero is called the ___________________.

origin

What type of acceleration would best describe the motion of a baseball dropped from the roof of a building?

positive acceleration

What type of acceleration would best describe the motion of a girl on a skateboard going around a corner at a speed of 3 m/s?

positive acceleration

Acceleration

rate of change of velocity

A _______ _____ is needed to determine the position of an object.

reference point

Velocity includes the ______ and ________ of the object.

speed ; direction

What is instantaneous speed?

speed at a given point in time ; when something is speeding up or slowing down

Isaac Newton

stated rules that described the effects of forces on the motion of objects

What is speed?

the distance an object travels per unit of time

What is displacement?

the distance and direction of an object's change in position from the starting point

What is velocity?

the speed of an object and the direction of its motion

What is average speed?

total distance traveled divided by the total time of travel

True or false. A projectile is an object moving in a curved path under the influence of gravity only.

true

True or false. An object that is slowing down is also accelerating.

true

True or false. If an object is at rest, it tends to remain at rest.

true

True or false. In general, the independent variable is plotted on the x-axis of a graph.

true

True or false. The slope of a line is the ratio of rise to run

true

True or false. When there is acceleration, a position vs. time graph is a curve.

true

If an object is moving, it will have ________ motion. The object will keep moving at the same speed and in the same directions unless an _________ ____ changes it.

uniform ; unbalanced force

If the direction of a motion doesn't changed and the object moves in a straight line, the change in ________ is the same as the change in ______.

velocity ; speed

When will velocity change in an object?

when a force changes

When does motion occur?

when an object changes its position relative to a reference point

When does acceleration occur?

when an object changes its speed, direction, or both

Net force

when two or more forces act on an object at the same time ; mass times acceleration

The velocity of an object at rest is at _____, unless a force makes it move.

zero