2. A train 75 metres long is running with a speed of 20 km/hr. It will pass a standing man in :
a. 12 seconds
b. 13.5 seconds
c. 14 seconds
d. 15.5 seconds
Answer: B
Explanation:
Speed of the train = $\left( {20 \times \dfrac{5}{{18}}} \right)$ m/sec = $\left( {\dfrac{{50}}{9}} \right)$ m/sec
Time taken by the train to pass the man = $\dfrac{\text{Train Length}}{{Speed}}$ = $\dfrac{{75}}{{\left( {50/9} \right)}}$ = $\left( {75 \times \dfrac{9}{{50}}} \right)$ sec = 13.5sec
3. A speed of 16 metres per second is the same as :
a. 40.3 km/hr
b. 57.6 km/hr
c. 51.16 km/hr
d. None of these
4. A train 250 metres long, running with a speed of 50 km/hr will pass an electric pole in :
a. 30 seconds
b. 18 seconds
c. 72 seconds
d. 60 seconds
Answer: B
Explanation:
Speed of the train = $\left( {50 \times \dfrac{5}{{18}}} \right)$ m/sec = $\left( {\dfrac{{125}}{9}} \right)$ m/sec
Time taken by the train to pass the pole = $\dfrac{\text{Train Length}}{{Speed}}$ = $\dfrac{{250}}{{\left( {125/9} \right)}}$ = $\left( {250 \times \dfrac{9}{{125}}} \right)$ sec = 18sec
5. A train 300 metres long passes a standing man in 15 seconds. The speed of the train is :
a. 40 km/hr
b. 50 km/hr
c. 60 km/hr
d. 72 km/hr
6. A train running at the speed of 45 kmph took 12 seconds in passing a certain point. Then the length of the train must be :
a. 90 meters
b. 120 meters
c. 150 meters
d. 540 meters
Answer: C
Explanation:
Speed = $\left( {45 \times \displaystyle\frac{5}{{18}}} \right)$ m/sec = $\left( {\displaystyle\frac{{25}}{2}} \right)$ m/sec
Length of the Train = $(Time \times Speed)$ = $\left( {12 \times \dfrac{{25}}{2}} \right)$ = 150 m
Length of the train = 150 m