In one-dimensional motion, which scenario is an example of negative acceleration (taking the positive direction to be to the right)?

• A. A car moving to the left slows from $20\text{m/s}$ to $10\text{m/s}$ in $5\text{s}$.
• B. A car moving to the right slows from $20\text{m/s}$ to $10\text{m/s}$ in $5\text{s}$.
• C. An object moves to the right at a constant velocity of $15\text{m/s}$ for $10\text{s}$.
• D. A car moving to the right speeds up from $10\text{m/s}$ to $20\text{m/s}$ in $5\text{s}$.

Answer: (B)