росто
The driver of a car travelling at a speed of 20 m/s, wishes to overtake a truck that is moving with a
constant speed of 20 m s' in the same lane. The car's maximum acceleration is 0.5 ms. Initially the
vehicles are separated by 40 m, and the car returns back into its lane after it is 40 m ahead of the truck
The car is 3 m long and the truck 17m long
Find the minimum time required for the car to pass the truck and return back to its lane?
(A) 10 second (B) 20 second (C) 15 second (D) none of these
Answers
Answer:
20 sec
Explanation:
The driver of a car travelling at a speed of 20 m/s, wishes to overtake a truck that is moving with a
constant speed of 20 m s' in the same lane. The car's maximum acceleration is 0.5 ms. Initially the
vehicles are separated by 40 m, and the car returns back into its lane after it is 40 m ahead of the truck
The car is 3 m long and the truck 17m long
Distance to be covered by car
= Distance covered by truck + Car Behind truck + Truck Length + Car ahead Truck + Car Length
= Distance covered by truck + 40 + 17 + 40 + 3
= Distance Covered by truck + 100 m
Let say T secs is required
Distance Covered by truck = 20T
Distance to be covered by car = 20T + 100
Distance to be covered by car = S = ut + (1/2)at²
= 20T + (1/2)(0.5)T²
= 20T + 0.25T²
Equating both
20T + 0.25T² = 20T + 100
=> T² =100/0.25
=> T² = 400
=> T = √400
=> T = 20 sec
20 sec required for the car to pass the truck and return back to its lane