Question

accelerating or not
yes no a car making a turn at constant speed
yes no a car driving in a circle at constant speed of 35 mph
yes no a car speeding up on a straight ramp
yes no an suv cruising i - 80 west at a steady speed
yes no a truck starts moving after waiting for a stoplight
yes no a helicopter ascending straight upward at 15 mph
yes no a person walking straight east at constant speed
yes no a ball following a curved path in air
yes no a car skidding to a stop
yes no a rocket launch from rest

Explanation:

Step1: Recall acceleration definition

Acceleration is a change in velocity. Since velocity is a vector (has magnitude - speed and direction), a change in speed or direction means acceleration.

Step2: Analyze each case

• A car making a turn at constant speed: Changes direction, so has acceleration (YES).
• A car driving in a circle at constant speed of 35 mph: Changes direction, so has acceleration (YES).
• A car speeding up on a straight ramp: Increases speed, so has acceleration (YES).
• An SUV cruising I - 80 West at a steady speed: No change in speed or direction, so no acceleration (NO).
• A truck starts moving after waiting for a stoplight: Changes from rest to motion, speed changes, so has acceleration (YES).
• A helicopter ascending straight upward at 15 mph: No change in speed or direction, so no acceleration (NO).
• A person walking straight east at constant speed: No change in speed or direction, so no acceleration (NO).
• A ball following a curved path in air: Changes direction, so has acceleration (YES).
• A car skidding to a stop: Decreases speed, so has acceleration (YES).
• A rocket launch from rest: Increases speed from 0, so has acceleration (YES).

Answer:

1. YES
2. YES
3. YES
4. NO
5. YES
6. NO
7. NO
8. YES
9. YES
10. YES