Question

can the velocity of an object be nonzero and the acceleration be zero at the same time? multiple choice impossible to determine since acceleration is a scalar while velocity is a vector. no, since velocity and acceleration are directly proportional. yes. an object speeding up while moving in a straight line has nonzero speed but has zero acceleration. yes. an object moving in a straight line at constant speed has zero acceleration.

Explanation:

• Acceleration is the rate of change of velocity. If velocity (speed and direction) is constant (straight - line, constant speed), acceleration ($a=\frac{\Delta v}{\Delta t}$, $\Delta v = 0$ here) is zero, while velocity is non - zero.
• The first option is wrong as acceleration is a vector. The second is wrong as velocity and acceleration aren't directly proportional. The third is wrong because an object speeding up has non - zero acceleration.

Answer:

Yes. An object moving in a straight line at constant speed has zero acceleration.