An object starts from rest and travels in a straight line with an acceleration of 2.0 m/s² for 3.0 seconds. It then reduces its acceleration to 1.0 m/s² for 5.0 additional seconds. The magnitude of the velocity at the end of the 5.0 second interval is A) 6.0 m/s. B) 18 m/s. C) 8.0 m/s. D) 4 m/s. E) 11 m/s.

Question

Quizplus · Accepted Answer

To find the magnitude of the velocity at the end of the 8.0-second interval (3.0 seconds at 2.0 m/s^2 and 5.0 seconds at 1.0 m/s^2), we calculate the velocity at the end of each interval and sum them. For the first interval: $v = u + at = 0 + (2.0 \, m/s^2)(3.0 \, s) = 6.0 \, m/s$. For the second interval, the initial velocity is 6.0 m/s, so $v = u + at = 6.0 \, m/s + (1.0 \, m/s^2)(5.0 \, s) = 6.0 \, m/s + 5.0 \, m/s = 11.0 \, m/s$.

An Object Starts from Rest and Travels in a Straight