A car starts from rest and travels a distance of 100 m in 20 seconds, with constant acceleration. The magnitude of the velocity of the car is at the end of the 20 second interval is
A) 25 m/s.
B) 20 m/s.
C) 15 m/s.
D) 10 m/s.
E) 5.0 m/s.

Question

Quizplus · Accepted Answer

The velocity can be found using the formula for constant acceleration: $v = u + at$, where $v$ is the final velocity, $u$ is the initial velocity (0 m/s since the car starts from rest), $a$ is the acceleration, and $t$ is the time. To find the acceleration, we use the formula $s = ut + \frac{1}{2}at^2$, where $s$ is the distance (100 m), $u$ is the initial velocity (0 m/s), and $t$ is the time (20 s). Substituting the given values, we get $100 = 0 + \frac{1}{2}a(20)^2$, solving for $a$ gives $a = 0.5$ m/s$^2$. Substituting $a$ back into the first formula gives $v = 0 + 0.5 \times 20 = 10$ m/s.

A Car Starts from Rest and Travels a Distance of 100