Question

chantelle is riding his bicycle towards the east. which of the following situations is impossible? he has ......- velocity is directed east, and acceleration is directed west.- velocity is directed east, and acceleration is directed east.- constant non-zero velocity and changing acceleration.- constant non-zero acceleration and changing velocity.

Explanation:

• When velocity is east and acceleration west, this is slowing down while moving east, which is possible.
• When velocity and acceleration are both east, this is speeding up east, which is possible.
• Constant non-zero velocity means acceleration must be 0 (since acceleration is the rate of change of velocity, $\vec{a}=\frac{\Delta \vec{v}}{\Delta t}$). A changing non-zero acceleration would require velocity to change, so this is impossible.
• Constant non-zero acceleration means velocity must change (since $\Delta \vec{v}=\vec{a}\Delta t$), so this is possible.

Answer:

constant non-zero velocity and changing acceleration.