Which of the following represents a case in which you are not accelerating?

• A. Slowing down to a stop
• B. Driving in a straight line at a constant $v$
• C. Speeding up while moving forward
• D. Turning a corner at a constant $v$

Answer: (B)

Verified step by step guidance

1. Understand that acceleration is defined as any change in velocity, which includes changes in speed or direction.
2. Analyze each option: 'Slowing down to a stop' involves a decrease in speed, so acceleration is present.
3. 'Speeding up while moving forward' involves an increase in speed, so acceleration is present.
4. 'Turning a corner at a constant speed' involves a change in direction, which means velocity changes, so acceleration is present.
5. Therefore, the only case with no acceleration is 'Driving in a straight line at a constant velocity' because neither speed nor direction changes.