Question

YOU ARE DRIVING AT 35m/s PON A HIGHWAY WHEN YOU COME UP BEHIND A TRUCK MOVING AT 25m/s IN THE SAME DIRECTION .YOU'D LIKE TO HAVE 20m OF SPACE BETWEEN THE FRONT OF YOUR CAR AND THE BACK OF THE TRUCK WHEN YOU MOVE INTO THE PASSING LANE AND 20M OF SPACE BETWEEN THE BACK OF YOUR CAR AND THE FRONT OF THE TRUCK WHEN YOU SWITCH BACK INTO THE ORIGINAL LANE .IF THE TRUCK IS 10m LONG , HOW MANY SECONDS DO YOU NEED IN THE PASSING LANE IF YOU KEEP YOUR SPEED CONSTANT AT 35m/s

Answer 1

This problem can be solved by relative velocity concept

speed of the truck = 25 m/s

length of the truck = 10 m

speed of the car = 35 m/s

and the distance between car and truck = 20 + 20 = 40 m

velocity of Car with respect the velocity of tri\uck is given by

Displacement

Time required to cover this distance is

So the time required to pass the truck is = 5 sec