VCJH Science 8 Unit 6

Question 0

2. What is a vector?

Answer 0

A vector is any measurement that has both size and direction.

Question 1

1. Acceleration always refers to a(n)
   a) increaseinspeed.
   b) change in speed.
   c) changeindirection.
   d) change in velocity.

Answer 1

d) change in velocity.

Question 2

3. True or false: Acceleration is a vector.

Answer 2

true

Question 3

4. True or false: A change in direction without a change in speed is called velocity.

Answer 3

false

Question 4

5. True or false: Acceleration can never be negative.

Answer 4

false

Question 5

6. A decrease in speed is called _____.

Answer 5

deceleration

Question 6

7. Give an example of acceleration. Clearly state what is changing and how it is changing.

Answer 6

Answers may vary. ​Sample answer:​ An example of acceleration is slowing down while riding a bike around a corner. Both speed and direction are changing.

Question 7

8. Describe what acceleration feels like in a moving car.

Answer 7

In a moving car, acceleration feels like a push against your body. The push is in the opposite direction as the acceleration. For example, when a car speeds up, you feel as though you are pushed backward. When a car turns right, you feel as though you are pushed to the left.

Question 8

9. How can you accelerate while walking without changing your speed?

Answer 8

You can accelerate while walking without changing your speed by changing your direction.

Question 9

10. _____ is the rate at which velocity changes.

Answer 9

Acceleration

Question 10

1. Terms used to describe relative direction include
   a) in.
   b) up.
   c) sideways.
   d) all of the above

Answer 10

d) all of the above

Question 11

2. North, south, east, and west are _____ directions.

Answer 11

cardinal

Question 12

3. On a map, directions are given by a symbol called a(n) _____.

Answer 12

compass rose

Question 13

4. True or false: The direction of motion is a vector.

Answer 13

false

Question 14

5. A vector is represented by a(n) _____.

Answer 14

arrow

Question 15

6. Draw vectors to represent two motions: 1 inch left and 2 inches down.

Answer 15

1 inch left: 2 inches down:
<------
|
|
|
|
¥

Question 16

7. In drawing a vector arrow , how do you represent distance?

Answer 16

Distance is represented by the length of the arrow.

Question 17

When drawing an arrow to represent a vector, how do you represent direction?

Answer 17

Direction is represented by the way the arrow points.

Question 18

9. If you are facing north, then east is to your
   a) left.
   b) right.
   c) back.
   d) none of the above

Answer 18

b) right

Question 19

10. When you give someone instructions for finding a place, why is it important to include direction as well as distance?

Answer 19

It is important to include direction as well as distance because distance alone could indicate any place on a circle with a radius of the given distance. Adding direction allows you to pinpoint the correct place.

Question 20

1. _____ is the length of the route between two points.

Answer 20

Distance

Question 21

2. The SI unit for distance is the _____.

Answer 21

meter

Question 22

3. English units of distance include the
   a) mile.
   b) square mile.
   c) mile per hour.
   d) all of the above

Answer 22

A Mile

Question 23

4. The SI unit that equals 1000 meters is the _____.

Answer 23

kilometer

Question 24

4. The SI unit that equals 1000 meters is the _____.

Answer 24

kilometer

Question 25

5. The SI unit that equals 0.01 meters is the _____.

Answer 25

centimeter

Question 26

6. True or false: A millimeter is longer than a centimeter.

Answer 26

false

Question 27

7. A yard is closest in distance to a a) millimeter. b) centimeter. c) kilometer. d) meter.

Answer 27

d) meter.

Question 28

8. What are some common tools or devices for measuring distance?

Answer 28

Answers may vary. ​Sample answer​: Some common tools or devices for measuring distance include rulers, yardsticks, tape measures, and car odometers.

Question 29

9. True or false: | To measure distance in SI units, you could use a meter stick.

Answer 29

true

Question 30

10. Explain how you could use a map to measure the distance between two places.

Answer 30

You could use a ruler to measure the distance between the two places on the map and then use the map scale to convert the map distance to the actual distance on the ground.

Question 31

1. _____ is a change in position.

Answer 31

Motion

Question 32

2. Another term for position is _____.

Answer 32

location

Question 33

3. Give three examples of motion.

Answer 33

Answers may vary. ​Sample answer​: Three examples of motion are a train moving along a track, a hand waving back and forth, and a ball rolling down an alley.

Question 34

4. True or false: Aspects of motion include speed and direction.

Answer 34

true

Question 35

5. Define frame of reference.

Answer 35

Frame of reference is something that is not moving with respect to an observer that can be used to detect motion.

Question 36

6. If you are riding on a bus with a friend, you can tell you are moving by observing the motion of a) your friend in the seat beside you. b) the bus driver at the front of the bus. c) objects like trees and houses outside the windows. d) two of the above

Answer 36

c) objects like trees and houses outside the windows.

Question 37

7. What is your frame of reference for detecting the motion of the bus you are riding in? a) yourfriend b) the bus driver c) objects outside the windows d) two of the above

Answer 37

c) objects outside the windows

Question 38

8. True or false: The bus driver’s frame of reference is the passenger directly behind him.

Answer 38

false

Question 39

9. True or false: The frame of reference of an outside observer of the bus might be a house across the street.

Answer 39

true

Question 40

10. If you are sitting on a stationary bus, which frame of reference might make you think the bus has started moving? a) The car in the next lane starts moving. b) A passenger moves to the back of the bus. c) The bus driver turns to look through the windshield. d) none of the above

Answer 40

a) The car in the next lane starts moving.

Question 41

1. The y­axis of a position­time graph represents _____.

Answer 41

position

Question 42

2. The x­axis of a position­time graph represents _____.

Answer 42

time

Question 43

3. True or false: A position­time graph shows how far an object has traveled at any given time since it started moving.

Answer 43

true

Question 44

4. True or false: A position­time graph shows the direction(s) the moving object has traveled relative to the starting position.

Answer 44

true

Question 45

5. The slope of a position­time graph can be used to find the moving object’s a) velocity. b) position. c) acceleration. d) none of the above

Answer 45

a) velocity

Question 46

6. Explain the motion of an object if its position ­time graph is horizontal.

Answer 46

If an object’s position­time graph is horizontal, its position is not changing with time. Therefore, the object must not be moving.

Question 47

7. True or false: The steeper the line on a position­time graph, the faster the object’s motion is changing.

Answer 47

true

Question 48

8. What is the formula for calculating the average velocity of a moving object? a) average velocity = ​Δ​d/​Δ​t b) average velocity = ​Δ​t/​Δ​d c) averagevelocity=​Δ​dx​Δ​t d) average velocity = ​Δ​d + ​Δ​t

Answer 48

a) average velocity = ​Δ​d/​Δ​t

Question 49

9. Assume that a car moves at a constant velocity from point A to point B. The distance between points A and B is 100 miles, and it takes the car 2 hours to travel this distance. Then the car stays at point B for 1 hour before moving on to point C at a constant velocity. The distance between points B and C is 50 miles, and it takes the car 2 hours to travel this distance. Draw a position ­time graph to represent the motion of a car during the entire 5 ­hour period.

Answer 49

Students’ graphs should have the x­ (time) and y­ (distance) axes properly labeled, and the lines of their graphs should correctly represent the motion described in the question.

Question 50

10. Calculate the velocity of a car traveling 100 miles in two hours between hours 0 and 2, staying parked hours 2 to 3, and traveling 50 miles in two hours between hours 3 and 5.

Answer 50

Between hours 0 and 2, the velocity of the car is 50 miles per hour. Between hours 2 and 3, the velocity is 0 miles per hour. Between hours 3 and 5, the velocity is 25 miles per hour.

Question 51

1. How fast or slow something moves is its _____.

Answer 51

speed

Question 52

2. True or false: Speed determines how far something moves in a given amount of time.

Answer 52

true

Question 53

3. The SI unit for speed is a) cm/s. b) m/s. c) m/h. d) km/h.

Answer 53

c) meters/hr

Question 54

4. What formula can you use to calculate average speed?

Answer 54

Average speed = distance/time.

Question 55

If you ride your bike 20 miles and it takes you 120 minutes, what is your average speed? a) 6m/h b) 10 m/h c) 20m/h d) 60 m/h

Answer 55

b) 10 m/h

Question 56

Your speed at any given moment is called your _____ speed.

Answer 56

instantaneous

Question 57

If you know your average speed and how long you have been traveling, then you can calculate your distance with the formula a) distance=speed/time. b) distance = speed x time. c) distance=time/speed. d) none of the above

Answer 57

b) distance = speed x time.

Question 58

To calculate the amount of time it takes to travel a given distance at a certain speed, you would use the formula a) time=distance/speed. b) time = distance x speed. c) time=speed/distance. d) none of the above

Answer 58

a) time=distance/speed.

Question 59

If you walk at an average speed of 5 km/h for 30 minutes, how far will you walk?

Answer 59

2.5 km.

Question 60

If you run at an average speed of 10 m/h, how long will it take you to run 2.5 miles?

Answer 60

It will take you 1⁄4 hour, or 15 minutes.

Question 61

How fast an object is moving is its _____.

Answer 61

speed

Question 62

The measure of both speed and direction is _____.

Answer 62

velocity

Question 63

Any measurement that includes both size and direction is called a(n) _____.

Answer 63

vector

Question 64

True or false: Velocity is a vector.

Answer 64

true

Question 65

If you represent velocity with an arrow, the length of the arrow represents a) speed. b) distance. c) direction. d) acceleration.

Answer 65

a) speed

Question 66

Explain how you can calculate the average velocity of a moving object that does not change direction.

Answer 66

by dividing the distance traveled by the time it takes to travel that distance. D2-D1/T2-T1

Question 67

True or false: The SI unit for velocity is km/h.

Answer 67

false

Question 68

The slowest moving object is the object represented by a vector with the _____arrow. Shortest/Longest

Answer 68

Shortest

Question 69

True or false: The objects represented by vectors with the same length but heading in different directions have the same velocity.

Answer 69

false

Question 70

Two vectors moving in the same direction have the same velocity?. T/F

Answer 70

False. Must also have the same speed (length of vector arrow)