Question

14. A motorist traveling at 70 ms¹ passes a policeman who immediately accelerates to catch the motorist. If the policeman catches the motorist in 16 s, what is the policeman's acceleration?​

Answer 1

We can use the following kinematic equation to solve this problem:

d = vt + (1/2)at²

where d is the distance traveled, v is the initial velocity, t is the time, a is the acceleration, and we are solving for a.

Let's assume that the motorist and the policeman both start from the same point and the distance between them is the distance traveled by the motorist during the 16 s it takes for the policeman to catch up. We can calculate this distance as:

d = vt = (70 ms¹)(16 s) = 1120 m

Now we can use the same equation to solve for the policeman's acceleration:

d = vt + (1/2)at²

1120 m = 0 + (1/2)a(16 s)²

Simplifying and solving for a, we get:

a = (2 x 1120 m) / (16 s)²

a = 175 m/s²

Therefore, the policeman's acceleration is 175 m/s².