Ques:- A man sees a train passing over a bridge 1 km long. The length of the train is half that of the bridge. If the train clears the bridge in 2 minutes, the speed of the train is
A. 30 km/hr
B. 40 km/hr
C. 45 km/hr
D. 55 km/hr
45km
45km/hr
Total distance=1+(1/2)=3/2
Time in hours=60/2
Speed of train=3/2×(60/2)=45km/hr
Total distance covered by train = 1km + 0.5km =1.5km
Time is 2minutes, this convert to hour is 2/60 = 0.033
speed =distance/time
1.5/0.033
= 45.45km/hr
45.45 km/hr approx 45km/hr
In two minutes trains travels 1km
In one minute it will travels0.5km
1 hour = 60 minutes
Therefore it’s speed per hour is 0.5*60
i.e 30 km/h
Correct option is
B
∴ Speed of the train=45 km/hr
Total distance= 1km+0.5 km=1.5km=1500m
Time taken =2min=120seconds
Speed=distance/time=1500/120=12.5m/s
Speed( in km/hr)=12.5*18/5=45
30km/hr
because train passed 1km total distance starting bridge to ending take total time is 2 minitues
so that=1/0.033=30.30
d = 1000 + 500 (distance to drive in meter. bridge + train size)
t = 120 (2 minutes to second)
s = d / t (12.5 m/s)
convert m/s to km/h = x 3.6
12.5 x 3.6 = 45 km/h
the train drive 45 km/h
man saw a train when it has already covered half distance of the bridge so remaining distance of the bridge is 0.5km
The length of the train is half of the bridge = 0.5km
so total distance = 0.5+0.5=1KM
total time is 2min
so speed= 1/(2/60) = 30KM/Hr
formula
x m/s=x*(18/5) km/hr
1500/120=12.5
speed= 12.5*(18/5)
45
45KM
45km/hr
45km/h
45
S=(length of the train+/length of the bridge)/time
length of the train = length of the bridge/2 = 1km = 1000/2
time = 2 m = 2*60 = 120 s
S=(1500/120)*(18/5)=45 km/h
30km/hr
LENGTH OF BRIDGE = 1KM = 1000 M
LENGTH OF TRAIN = LENGTH OF BRIDGE/2 = 500 M
TOTAL DISTANCE = 1000 + 500 = 1500 M
IF TRAIN CROSS THE 1500 M IN 2 MINUTES
SPEED OF TRAIN = 1500 * 60/2
45000 M
45 KM
45
ridge Length of Bridge = 1 km =1000m
Length of train = half of Bridge = 1000/2 = 500m
total Distance Cover by the train = 1000 + 500 = 1500m
length of train = (1500*3600) / (120 * 1000) = 45 km/h
45 km/hr