chapter 11 physical science

Acceleration can be the result of a change in _______ at a constant speed. (for example: riding a bicycle around a curve)

direction

Sometimes knowing only the speed of an object isn't enough. You also need to know the ____ of the objects motion.

direction

To describe motion, you must state the ____ the object is moving as well as how _____ the object is moving. You must also tell its location at a certain time.

direction, fast

Length of a path between two points

distance

______ is the length of a path between two points. when an object moves in a straight line, the distance is the length of the line connecting the objects starting point and its ending point.

distance

How are distance and displacement different?

distance is the length of a path between two points. displacement is the direction from the starting point and the length of a straight line from the starting point to the ending point.

on a speed-time graph of a bicycle slowing to a stop, a line sloping _______ represents the bicycle decelerating

downward

To describe an objects position relative to a given point, you need to know how ___ away and in what _____ the object is from that point. displacement provides this information.

far, direction

A longer vector represents a _____ speed, and a shorter one a _____ speed.

faster, slower

How fast the passengers on a train are moving depends on the ____ ___ ______ chosen to measure their motion

frame of reference

System of objects that are not moving with respect to one another

frame of reference

Movement of an object toward earth solely because of gravity

free fall

Each second an object is in free fall, its velocity increases downward by 9.8 meters per second squared. The change in the objects speed is 9.8 m/s^2, the acceleration due to _____

gravity

A steeper slope on a distance-time graph indicates a _____ speed

higher

The vectors length depends on how fast what?

how fast velocity is changing

If you are coasting downhill on a bicycle, your velocity ______, and your acceleration is ________

increases, positive

An increasing slope on a distance time graph of accelerated motion means that the speed is _______

increasing

The acceleration at a specific point on a distance-time graph is the _________ ________.

instantaneous acceleration

What is instantaneous acceleration?

instantaneous acceleration is how fast a velocity is changing at a specific instant

Rate at which an object is moving at a given moment in time

instantaneous speed

_______ ___ is the rate at which an object is moving at a given moment in time

instantaneous speed

For very large distances, it is more common to make measurements in ________

kilometers

The SI unit for distance that would be most appropriate for measuring the distance between two cities is _______

kilometers

The magnitude can be size, ____, or ______

length, or amount

Displayed data forms straight line parts

linear graph

The SI unit for measuring distance is the _____

meter

What is the unit for velocity?

meters per second

What is the unit for acceleration?

meters per second squared

A distance-time graph is a good way to describe _____

motion

If the velocity decreases, the acceleration is ______.

negative

Mike pedals up a hill and gradually slows from 20m/h to 5km/h. This is an example of_______ acceleration

negative

A curve connects the data parts that are plotted

non linear graph

in a ________ ___, a curve connects the data points that are plotted

nonlinear graph

If the velocity increases, the acceleration is _____.

positive

Movement in relation to a frame of reference

relative motion

______ ____ is movement in relation to a frame of reference

relative motion

Vector sum of two or more vectors

resultant factor

____ is the change In the vertical axis value divided by the change in the horizontal axis value

slope

If the motion is in a straight line, velocity can be treated as _____, and acceleration is the change in speed divided by time.

speed

Ratio of distance an object moves to the amount an object moves

speed

______ is the ratio of the distance an object moves to the amount of time the object moves

speed

Sometimes motion is characterized by changes in both _____ and _____ at the same time

speed and direction

The _______ in a car measures the cars instantaneous speed.

speedometer

If two displacements are in opposite directions, the magnitudes ______ from each other

subtract

How do you determine a change in velocity?

subtract one velocity vector from another

A horse on the carousel is traveling at a constant speed, but is accelerating because why?

the direction is constantly changing

How can you find the speed from a distance-time graph?

the slope of a line on a distance-time graph is the speed

How do velocities add?

two or more velocities add by vector addition

Acceleration and Velocity are both ______ quantities.

vector

Quantity that has magnitude and direction

vector

In science, acceleration applies to any change in an object's ____

velocity

Sometimes the motion of an object involves more than one _____

velocity

Together, the speed and direction at which an object is moving

velocity

Together, the speed and direction in which an object are moving are called ______

velocity

How are speed and velocity different?

velocity is a description of both speed and direction of motion. velocity is a vector.

You can use a graph to calculate acceleration. Graph speed on the _______ axis and time on the _______ axis.

vertical, horizontal

For an object that is standing still, the acceleration vector is ____

zero

A car traveling at 10m/s starts to decelerate steadily. It comes to a complete stop in 20 seconds. What is its acceleration?

-0.5m/s^2

You travel 18km west of your home and then turn around and start going back home. After traveling 4km east, what is your displacement from your home?

14 km west

You travel 12km east of your home, stop at a red light and continue traveling 7 km east. What Is your final displacement from your home?

19 km east.

A child drops a ball from a bridge. The ball strikes the water under the bridge 2.0 seconds later. What is the velocity of the ball when it strikes the water?

20m/s

An airplane travels down a runway for 4.0 seconds with an acceleration of 9.0m/s^2. What is its change in velocity during this time?

36 m/s

A ball rolls down a ramp, starting from rest. After 2 seconds, its velocity is 6 meters per second. What is the Acceleration of the ball?

3m/s^2

A woman jogs 8 kilometers in one hour, stops at a park for one hour, and then walks 7 kilometers in two hours. What is her average speed for the outing?

5km/hour

A sports car can accelerate from 0m/s to 28m/s in four seconds. What is the acceleration of the car?

7m/s^2

You travel 35 kilometers in 0.4 hour, followed by 53 kilometers in 0.6 hour. What is your average speed?

88km/hour

Objects falling near Earth's surface accelerate downward at a rate of _____

9.8m/s^2

How are changes in velocity described?

The rate at which velocity changes is acceleration

How does a speed-time graph indicate acceleration?

The slope of a speed-time graph is the acceleration.

If you were to sketch a displacement-time graph for an object experiencing constant acceleration, what would they look like?

The speed-time graph would be linear; the displacement -time graph would be nonlinear

What is needed to describe motion completely?

a frame of reference is necessary

How do you add displacements?

a vector is a quantity that has magnitude and direction, add displacements using vector addition

A roller coaster produces ____________ due to changes in both speed and direction.

acceleration

Rate at which velocity changes

acceleration

The slope is the change in speed divided by change in time, which is equal to the _______

acceleration

What is the formula to find acceleration?

acceleration= final velocity - initial velocity / time

Acceleration involves a change in velocity or direction or both, so the vector of acceleration can point in __ ______

any direction

Two ways to express the speed of an object are ____ and ______ speed

average and instantaneous

Total distance traveled divided by total time spent

average speed

_______ ____ is the total distance traveled, d, divided by the time, t, it takes to travel that distance

average speed

How are instantaneous speed and average speed different?

average speed is computed for the entire duration of a trip, and instantaneous speed in measured at a particular instant

Distances that are smaller than a meter are measured in ______

centimeters

________acceleration is represented on a speed-time graph by a straight line.

constant

Steady change in velocity

constant acceleration

_______ ______ is a steady change in velocity

constant acceleration

The velocity of an object moving in a straight line changes at a ______ ____ when the object is experiencing ______ ______

constant rate, constant acceleration

Acceleration is rarely _____, and motion is rarely in a ______ ____

constant; straight line

accelerated motion is represented by a ____line on a distance-time graph

curved

_________ is an acceleration that slows an object's speed

deceleration

Constant negative acceleration _________ speed

decreases

If you continue coasting on level ground, your velocity ______, and your acceleration is _______.

decreases, negative

Acceleration can be caused by negative and positive changes in speed. Negative meaning _______, and positive meaning ______

decreasing, increasing

Name three vector quantities.

1. Displacement 2. Velocity 3. Acceleration

true or false: If an object experiences a steady velocity change in a straight line, it is undergoing constant acceleration.

True

How can you calculate acceleration?

You calculate acceleration for straight-line motion by dividing the change in velocity by the total time.