A car of length 4.3m is travelling at 105km/h. It passes over a bridge of length 36m. Calculate the time, in seconds, it takes to pass over the bridge completely
Answers
Answer:
1.53
Step-by-step explanation:
A car of length 4.3 m is travelling at 105 km/h. It passes over a bridge of length 36 m. Calculate the time, in seconds, it takes to pass
The speed of the car is 105 km/ hr
= 105 x 1000 / 60 x 60
= 105000 / 3600
= 29.166 m / s
So distance the car has to cover will be 36 + 4.3 + 4.3 = 44.6 m
Now the car will clear the bridge in t = d /s = 44.6 / 29.166 = 1.53 secs
The time, in seconds, it takes to pass over the bridge completely is 1.53 secs
Answer: 1.38 s
Step-by-step explanation:-
What you basically have to do is:-
Take-out Distance - 36 + 4.3
= 40.3 m
Take-out Speed - 105 km/h to m/s
= 105 x 1000/60 x 60
= 105000/3600
=> 29.2 m/s (rounded off)
Take-out Time - D/S
= 40.3/29.2
= 1.38 s
Therefore, this is the final answer!
Now, if you are wondering why did we add '4.3' to 36...the reason is because the question specifies the word "completely", this means that even when we have crossed the bridge (which is 36m); the back of the car has not completely crossed the bridge, and by adding the car's length we solve this problem! :)
HAPPY LEARNING!! ^^