Question

question 18 (1 point)
can an objects velocity change direction when its acceleration is constant? support your answer with an example.
no, this is not possible because it is always speeding up.
no, this is not possible because it is always speeding up or always slowing down, but it can never turn around.
yes, this is possible, and a rock thrown straight up is an example.
yes, this is possible, and a car that starts from rest, speeds up, slows to a stop, and then backs up is an example.
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Explanation:

To determine the answer, we analyze each option:

• First two options ("No...") are incorrect. Acceleration (e.g., gravity) can be constant while velocity direction changes.
• Third option: A rock thrown straight up has constant acceleration (gravity, \(a = -9.8\,\text{m/s}^2\) downward). Initially, velocity is upward (slowing down), then velocity becomes downward (speeding up) — direction changes with constant acceleration.
• Fourth option: A car slowing to a stop and backing up involves changing acceleration (not constant), so it’s invalid.

Answer:

C. Yes, this is possible, and a rock thrown straight up is an example.