Physics Unit 1 Quiz 2

1. Which of the following units is the SI unit of velocity?

Meter

Meter per second

Meter per second per second

Second per meter

The SI unit of velocity is meter per second. Velocity is defined as the rate of change of displacement with respect to time, and it is measured in meters per second. This unit represents the distance traveled in meters divided by the time taken in seconds, which gives the speed of an object in a particular direction.

Explanation

The SI unit of velocity is meter per second. Velocity is defined as the rate of change of displacement with respect to time, and it is measured in meters per second. This unit represents the distance traveled in meters divided by the time taken in seconds, which gives the speed of an object in a particular direction.

2. Which straight-line acceleration indicates an increase in speed?

blank to the power of blank

0 m/s2

-15 m/s2

4 m/s2

All of the above

An acceleration of 4 m/s2 indicates an increase in speed because acceleration is the rate at which an object's velocity changes. A positive acceleration value means that the velocity is increasing, while a negative acceleration value indicates a decrease in velocity. Therefore, an acceleration of 4 m/s2 suggests that the object is gaining speed.

Explanation

An acceleration of 4 m/s2 indicates an increase in speed because acceleration is the rate at which an object's velocity changes. A positive acceleration value means that the velocity is increasing, while a negative acceleration value indicates a decrease in velocity. Therefore, an acceleration of 4 m/s2 suggests that the object is gaining speed.

3. On a speed-time graph, a line with a negative slope indicates that the object is

Speeding up

Slowing down

Not moving

Traveling at a constant speed

A line with a negative slope on a speed-time graph indicates that the object is slowing down. The slope of a line on a graph represents the rate of change, and in this case, a negative slope means that the speed is decreasing over time. This indicates that the object is decelerating or slowing down its motion.

Explanation

A line with a negative slope on a speed-time graph indicates that the object is slowing down. The slope of a line on a graph represents the rate of change, and in this case, a negative slope means that the speed is decreasing over time. This indicates that the object is decelerating or slowing down its motion.

4. On a distance vs. time graph, the line of an object at rest is a

Curved line with a slope of zero.

Flat line with a slope of zero.

Jagged line with a negative slope.

Curved line with a positive slope.

The line of an object at rest on a distance vs. time graph is a flat line with a slope of zero because when an object is at rest, it does not change its position over time. Therefore, the distance traveled remains constant, resulting in a horizontal line on the graph. The slope of this line is zero because there is no change in distance with respect to time.

Explanation

The line of an object at rest on a distance vs. time graph is a flat line with a slope of zero because when an object is at rest, it does not change its position over time. Therefore, the distance traveled remains constant, resulting in a horizontal line on the graph. The slope of this line is zero because there is no change in distance with respect to time.

5. The SI base unit used to measure mass is the

Meter

Second

Kilogram

Liter

The SI base unit used to measure mass is the kilogram. Mass is a fundamental property of matter and is measured using the kilogram as the base unit. The kilogram is defined as the mass of the International Prototype of the Kilogram, a platinum-iridium cylinder kept at the International Bureau of Weights and Measures in France. It is a standard unit of mass that is widely used in scientific and everyday measurements.

Explanation

The SI base unit used to measure mass is the kilogram. Mass is a fundamental property of matter and is measured using the kilogram as the base unit. The kilogram is defined as the mass of the International Prototype of the Kilogram, a platinum-iridium cylinder kept at the International Bureau of Weights and Measures in France. It is a standard unit of mass that is widely used in scientific and everyday measurements.

6. Moving from 0 m/s to 25 m/s in 8.0 s equals an average acceleration of

0.32 m/s

0.32 m/s^2

3.1 m/s

3.1 m/s^2

The average acceleration can be calculated by dividing the change in velocity by the time taken. In this case, the change in velocity is 25 m/s (from 0 m/s to 25 m/s) and the time taken is 8.0 s. Dividing 25 m/s by 8.0 s gives an average acceleration of 3.1 m/s^2.

Explanation

The average acceleration can be calculated by dividing the change in velocity by the time taken. In this case, the change in velocity is 25 m/s (from 0 m/s to 25 m/s) and the time taken is 8.0 s. Dividing 25 m/s by 8.0 s gives an average acceleration of 3.1 m/s^2.

7. A pitcher throws a baseball to home plate, a distance of 60.5 ft. The ball reaches home plate in 0.63 s. What is the velocity of the ball?

38 ft/s

38 ft/s toward home plate

96 ft/s

96 ft/s toward home plate

The velocity of the ball is 96 ft/s toward home plate because velocity is calculated by dividing the distance traveled by the time taken. In this case, the ball traveled a distance of 60.5 ft in 0.63 s, resulting in a velocity of 96 ft/s. The "toward home plate" part is included in the answer to specify the direction of the velocity.

Explanation

The velocity of the ball is 96 ft/s toward home plate because velocity is calculated by dividing the distance traveled by the time taken. In this case, the ball traveled a distance of 60.5 ft in 0.63 s, resulting in a velocity of 96 ft/s. The "toward home plate" part is included in the answer to specify the direction of the velocity.

8. The difference between speed and velocity is that velocity includes

Direction.

Distance.

Time.

Weight.

The difference between speed and velocity lies in the inclusion of direction. While speed only refers to the rate at which an object moves, velocity takes into account both the speed and the direction in which the object is moving. Therefore, velocity provides a more comprehensive description of an object's motion, as it specifies both the magnitude and the direction of the object's displacement.

Explanation

The difference between speed and velocity lies in the inclusion of direction. While speed only refers to the rate at which an object moves, velocity takes into account both the speed and the direction in which the object is moving. Therefore, velocity provides a more comprehensive description of an object's motion, as it specifies both the magnitude and the direction of the object's displacement.

9.

The graph above describes the motion of a cyclist. The graph illustrates that the acceleration of the cyclist

Is constant

Increases

Decreases

Is zero

The graph above shows the motion of a cyclist. From the graph, we can see that the velocity of the cyclist is increasing over time. Since acceleration is the rate of change of velocity, an increasing velocity indicates that the acceleration of the cyclist is also increasing. Therefore, the correct answer is "increases".

Explanation

The graph above shows the motion of a cyclist. From the graph, we can see that the velocity of the cyclist is increasing over time. Since acceleration is the rate of change of velocity, an increasing velocity indicates that the acceleration of the cyclist is also increasing. Therefore, the correct answer is "increases".

10. A cheetah can accelerate at up to 6.0 m/s². How long does it take for a cheetah to speed up from 10.5 m/s to 12.2 m/s?

0.28 s

1.7 s

3.5 s

10 s

The cheetah's acceleration is given as 6.0 m/s^2. To find the time it takes for the cheetah to speed up from 10.5 m/s to 12.2 m/s, we can use the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Rearranging the equation to solve for time, we have t = (v - u) / a. Plugging in the values, we get t = (12.2 - 10.5) / 6.0 = 0.28 s.

Explanation

The cheetah's acceleration is given as 6.0 m/s^2. To find the time it takes for the cheetah to speed up from 10.5 m/s to 12.2 m/s, we can use the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Rearranging the equation to solve for time, we have t = (v - u) / a. Plugging in the values, we get t = (12.2 - 10.5) / 6.0 = 0.28 s.