1.
_______________ is defined as the rate of change in position.
Correct Answer
A. Speed
Explanation
Speed is defined as the rate of change in position. It is a scalar quantity that only considers the magnitude of the change in position, without considering the direction. Speed can be calculated by dividing the distance traveled by the time taken. It is commonly expressed in units such as meters per second (m/s) or kilometers per hour (km/h).
2.
Speed with direction is called ________________.
Correct Answer
C. Velocity
Explanation
Velocity is the correct answer because it refers to the speed of an object in a specific direction. It is a vector quantity that takes into account both the magnitude (speed) and direction of an object's motion. Acceleration refers to the rate of change of velocity, deceleration is a type of acceleration that refers to the decrease in velocity, and constant speed refers to an object moving at the same speed without any change in velocity.
3.
To find acceleration the initial velocity is _________ from the final velocity and then _____ by the time it takes to change velocity.
Correct Answer
B. Subtracted, divided
Explanation
To find acceleration, the initial velocity is subtracted from the final velocity to determine the change in velocity. Then, this change in velocity is divided by the time it takes to change velocity. This calculation allows us to determine the rate at which an object's velocity is changing over time, which is known as acceleration.
4.
A body accelerates if it____________
Correct Answer
D. All possible choices
Explanation
A body accelerates if it speeds up, slows down, or changes direction. Acceleration is a measure of how an object's velocity changes over time, and any change in speed or direction indicates acceleration. Therefore, all the given choices - speeding up, slowing down, and changing direction - are correct explanations for when a body accelerates.
5.
The term that means a change in rate of velocity is ____________.
Correct Answer
A. Acceleration
Explanation
Acceleration is the correct answer because it refers to a change in the rate of velocity. Velocity is a vector quantity that includes both speed and direction, so when there is a change in velocity, it means that either the speed or the direction or both have changed. Acceleration specifically measures the rate at which velocity changes over time, whether it is an increase or decrease in speed or a change in direction. Therefore, acceleration is the term that best describes a change in rate of velocity.
6.
In order to calculate the velocity of an object you must know the time and the _________ (assuming the direction remains constant).
Correct Answer
B. Distance
Explanation
To calculate the velocity of an object, you need to know the time and the distance traveled. Velocity is defined as the rate of change of displacement, which is the change in position of an object. Distance is the total length of the path traveled by an object, and it is necessary to determine the displacement of the object over a specific time interval. Therefore, knowing the distance is crucial in calculating the velocity of an object, assuming the direction remains constant.
7.
An object moving at the same speed over a certain distance is said to be traveling at a_______________________.
Correct Answer
A. Constant Speed
Explanation
When an object is moving at the same speed over a certain distance, it is said to be traveling at a constant speed. This means that the object is maintaining a steady velocity without any changes in its speed or direction. It is important to note that constant speed does not necessarily mean that the object is moving at a high or low speed, but rather that it is maintaining a consistent rate of motion.
8.
The speed of an object at any given point in time is the object's ___________________.
Correct Answer
B. Instantaneous Speed
Explanation
The speed of an object at any given point in time is referred to as its instantaneous speed. This term is used to describe the speed of an object at a specific moment or instant, rather than an average speed over a given time period. Instantaneous speed provides information about how fast an object is moving at a particular point in time, allowing for a more detailed understanding of its motion.
9.
Do any of the cars experience negative acceleration?
Correct Answer
B. Car B, min 6-7
Explanation
Both Car A and Car B do not experience negative acceleration because neither car decelerates. Negative acceleration occurs when an object slows down or decelerates. Since both cars maintain a constant speed, they do not experience negative acceleration.
10.
The best way to describe the rate of motion of an object that changes speed several times is to calculate the object's ____________________
Correct Answer
A. Average speed
Explanation
When an object changes speed several times, the best way to describe its rate of motion is by calculating the object's average speed. Average speed takes into account the total distance covered by the object and the total time taken, giving a measure of the overall speed throughout the entire motion. This is more appropriate than constant speed, which implies a consistent velocity throughout the motion, or instantaneous speed, which refers to the speed at a specific moment in time. Acceleration, on the other hand, measures the rate at which the object's speed changes over time, which is not the same as describing the overall rate of motion.
11.
A constant velocity means acceleration is _____________.
Correct Answer
D. Zero
Explanation
A constant velocity means that there is no change in speed or direction over time. In other words, the object is moving at a steady rate without speeding up or slowing down. Since acceleration is the rate of change of velocity, a constant velocity implies that the acceleration is zero.
12.
What is the acceleration of car B from 1 min to 5 min?
Correct Answer
A. Positive
Explanation
The acceleration of car B from 1 min to 5 min is positive. This means that the car is increasing its speed during this time period.
13.
What is the acceleration of car A from 6 min to 10 min?
Correct Answer
C. Zero
Explanation
The acceleration of car A from 6 min to 10 min is zero. This means that the car maintains a constant velocity during this time interval, neither speeding up nor slowing down.