Let's go through each of these multiple-choice questions (MCQs) one by one to determine the correct alternative:
a. Velocity is a vector quantity and is defined per unit time as the rate of change of **displacement**, not distance. Displacement is the straight line distance in a specific direction from the starting position to the final position, while distance is the total path length traveled, regardless of direction.
The correct answer is:
B) displacement
b. Inertia is a property of matter that describes its resistance to any change in its state of motion. Inertia depends on the **mass** of an object; the greater the mass, the greater the inertia, and thus the more force is needed to change its motion. It does not depend on acceleration.
The correct answer is:
B) mass
c. The rate of change of velocity is called **acceleration**. When the velocity of an object changes, it is said to be accelerating. Acceleration can occur through changes in speed (magnitude of velocity), changes in direction, or both.
The correct answer is:
B) acceleration
d. On a velocity-time graph, the **slope** of the line represents acceleration since slope is change in vertical coordinate (which represents velocity) divided by change in horizontal coordinate (which represents time). If the slope is positive, the object is accelerating; if the slope is negative, the object is decelerating.
The correct answer is:
B) acceleration
