A highway motorist travels at a constant velocity of 45Km /h in a 30Km/h zone A motor-cyclist police - Physics - Motion In A Straight Line

Question

A highway motorist travels at a constant velocity of 45Km /h in
a 30Km/h zone A motor-cyclist police officer has been watching from
behind a bill board and at the Same moment the speeding motorist
passes the bill board; the police officer accelerates uniformly
from rest to overtake her If the acceleration of the police officer
is 10 km h-2 how long does betake to reach the motorist?

Neha Gupta · Accepted Answer

Let v be the velocity of the motorist = 45 km/h = 125 m/sit travels the distance d in time t
v = d/td = 12
5t ----(1)Policeman will cover the same distance in same time when start from rest with acceleration a = 10 km/h2 = 0
00077 m/s2d = ut + 12at212
5t = 0 +12×0 00077×t2t = 32467
5 st = 9 01 min