Question

a piece of driftwood floats straight down a stream at a constant speed. what is the acceleration of the object? a positive acceleration b negative acceleration c zero acceleration

Explanation:

Step1: Recall acceleration formula

Acceleration $a=\frac{\Delta v}{\Delta t}$, where $\Delta v = v_f - v_i$ is the change in velocity and $\Delta t$ is the change in time.

Step2: Analyze the given situation

The drift - wood is moving at a constant speed in a straight line. So, $v_f=v_i$, then $\Delta v = 0$.

Step3: Calculate acceleration

Substitute $\Delta v = 0$ into the acceleration formula $a=\frac{\Delta v}{\Delta t}$. We get $a = 0$ since $\Delta v = 0$ and $\Delta t>0$.

Answer:

C. zero acceleration