Question

it took 2 seconds for the ball to move between points a and d. the rate at which the ball moved is equal to its
a. ○ velocity.
b. ○ speed.
c. ○ inertia.

Explanation:

To solve this, we analyze the concepts:

• Velocity is a vector (includes direction and magnitude, calculated as displacement over time).
• Speed is a scalar (magnitude only, calculated as distance over time).
• Inertia is the tendency to resist motion change, not a rate of movement.

The ball moves from A to D (a path with direction, so displacement is considered for velocity, but the rate here refers to the magnitude with direction? Wait, no—wait, the key is: velocity is the rate of change of displacement (includes direction), speed is rate of distance (magnitude). But the problem says "the rate at which the ball moved"—velocity is the rate of motion with direction, speed is rate without direction. However, in the diagram, A to D is a path (maybe displacement). Wait, no—wait, the options: velocity is a vector (rate with direction), speed is scalar (rate without direction). But the question is about the rate of movement (which includes direction, so velocity). Wait, no—wait, let's recall: velocity = displacement / time (vector), speed = distance / time (scalar). The ball moves from A to D—so displacement is from A to D (a straight line? Or the path? Wait, the diagram shows a curved path? No, the dotted lines: A to B to C to D? Wait, the problem says "between points A and D"—so the displacement is from A to D (straight line), and the time is 2s. Velocity is displacement over time (rate with direction), speed is distance over time (rate without direction). But the question says "the rate at which the ball moved"—velocity is the rate of motion (includes direction), so the answer should be A? Wait, no—wait, maybe I confused. Wait, the options: A is velocity, B is speed, C is inertia. Inertia is not a rate, so eliminate C. Now, velocity is a vector (displacement/time), speed is scalar (distance/time). The problem says "the rate at which the ball moved"—movement rate with direction is velocity. So the correct answer is A? Wait, no—wait, maybe the diagram: if A to D is a straight line (displacement), then velocity is displacement over time. So the rate (velocity) is displacement/time. So the answer is A.

Answer:

A. velocity