Question Detail

PHY 101 Last Min Prep Objective Question

Question

Over a short interval near time t = 0 the coordinate of an automobile in meters is given by x(t) = 27t - 4.0t³, where t is in seconds. At the end of 1.0 s the acceleration of the auto is:
Options
A -2.0 m/s²
B -4.0 m/s²
C -12.0 m/s²
D -24 m/s²
Correct Answer
Correct Answer

Option D is the correct answer.

Detailed Explanation

Velocity v(t) = dx/dt = 27 - 12t². Acceleration a(t) = dv/dt = -24t. At t=1 s, a(1) = -24 × 1 = -24 m/s².

Hint

Acceleration is the second derivative of position with respect to time.

Question Info