Question

A child on a scooter starts from rest and travels in a straight line with an acceleration of 1.25 m/s² for 5.0 s. it then decreases its acceleration to 0.5 m/s² for another 4.5 s. the magnitude of the velocity at the end of the second interval is:

Answer 1

The magnitude of the velocity at the end of the second interval is 8.5 m/s.

Step-by-step explanation:

To solve this problem, we can break it into two intervals: the first interval where the acceleration is 1.25 m/s² for 5.0 s, and the second interval where the acceleration is 0.5 m/s² for 4.5 s.

In the first interval, we can use the equation v = u + at, where v is the final velocity, u is the initial velocity (which is 0 m/s in this case), a is the acceleration, and t is the time taken.

Plugging in the values, we find that the velocity at the end of the first interval is 6.25 m/s.

In the second interval, we can use the same equation to find the final velocity. The initial velocity is the velocity at the end of the first interval (6.25 m/s), the acceleration is 0.5 m/s², and the time is 4.5 s. Plugging in the values, we find that the velocity at the end of the second interval is 8.5 m/s.