During the same constant acceleration of 3.0 m/s^2 from rest, what is the velocity after 2.0 s?

During the same constant acceleration of 3.0 m/s^2 from rest, what is the velocity after 2.0 s?

• A. 4 m/s
• B. 6 m/s
• C. 8 m/s
• D. 10 m/s

Answer: (B)

When acceleration is constant, velocity changes linearly with time: v = v0 + a t. Starting from rest means v0 = 0, so v = a t. With a = 3.0 m/s^2 and t = 2.0 s, v = 3.0 × 2.0 = 6.0 m/s. The direction is the same as the acceleration, and the units (m/s) come from m/s^2 times seconds. So the velocity after 2 seconds is 6 m/s.

When acceleration is constant, velocity changes linearly with time: v = v0 + a t. Starting from rest means v0 = 0, so v = a t. With a = 3.0 m/s^2 and t = 2.0 s, v = 3.0 × 2.0 = 6.0 m/s. The direction is the same as the acceleration, and the units (m/s) come from m/s^2 times seconds. So the velocity after 2 seconds is 6 m/s.