Question

which scenario involves acceleration?
○ a motorcycle at constant speed on a highway
○ a recreational vehicle parked in a campground
○ a car decreasing its speed due to a red light
○ a teenager talking to friends at an intersection

Explanation:

Step1: Recall the definition of acceleration

Acceleration is a change in velocity. Velocity is a vector quantity (has both magnitude - speed, and direction).

Step2: Analyze each option

• Option 1: A motorcycle at constant speed on a highway. If the speed is constant (assuming straight - line motion, no direction change), the velocity is constant. So, no acceleration.
• Option 2: A recreational vehicle parked in a campground. The vehicle is at rest. Its velocity is \(v = 0\) and remains \(0\). No acceleration.
• Option 3: A car decreasing its speed due to a red light. Since the speed (magnitude of velocity) is changing, there is an acceleration. The acceleration is negative (deceleration).
• Option 4: A teenager talking to friends at an intersection. The teenager is at rest. Velocity is \(v=0\) and remains \(0\). No acceleration.

Answer:

C. a car decreasing its speed due to a red light