Chapter 2, Problem 1AC

A straight-line distance covered during a certain amount of time describes an object’s

a. speed.

b. velocity.

c. acceleration.

d. any of the above.

To determine

The term used for the straight-line distance covered during a certain period of time, from the following options.

Speed

Velocity

Acceleration

Any of the above

Answer to Problem 1AC

Solution:

Option (a) is correct.

Explanation of Solution

Introduction: The speed of an object defines how fast the object is moving with respect to time. It gives the magnitude of velocity of the object.

The expression for the speed is:

$\text{speed}=\frac{\text{distance travelled}}{\text{time}}$

Explanation:

Reason for the correct option:

Refer to the expression of speed. The speed is given as the ratio of the distance travelledand the time taken. The distance travelled may be a straight line.

Hence, option (a) is correct.

Reason for the incorrect options:

Option (b) is incorrect because velocity is defined as the displacement per unit time and the displacement can be equal to or less than the distance. But, in the problem statement, it is mentioned about the straight-linedistance. So, it is a wrong answer.

Option (c) is incorrect because acceleration is defined as the change of velocity in a certain period of time. But, in the problem statement, it is mentioned about the straight-linedistance. So it is a wrong answer.

Option (d) is incorrect because options (b) and (c) are incorrect and for option (d) to be correct, all the options (a), (b), and (c) should be correct. So it is a wrong answer.

Hence, options (b), (c) and (d) are incorrect.

Conclusion:

The straight-line distance covered during a certain time period is termed as speed.