Physics, asked by Parassingh3408, 1 year ago

A 100 m long train crosses a man traveling at 5km/h in opposite direction,in 7.2seconds then the velocity of train is

Answers

Answered by Robin0071
4
Solution:-

given by:-
length of train = 100 m
train crosses a man in time(t) = 7.2 s
both velocity =
 \frac{100}{7.2}  =  \frac{1000}{72}  =  \frac{125}{9} m {s}^{ - 1}
man traveling velocity = 5km/h
5 \times  \frac{5}{18}  =  \frac{25}{18} m {s}^{ - 1}
Train's velocity = 12.5 m/s
 \frac{125}{9}  -  \frac{25}{18}  \\  \frac{250 - 25}{18}  =  \frac{225}{18}  = 12.5 \: m {s}^{ -1 }

■I HOPE ITS HELP■
Answered by tiwaavi
6
Given conditions, 
Velocity of the man = 5 km/hr = 1.38 m/s. 

Length of the Train (or Distance) = 100 m. 
Time = 7.2 seconds. 

Let the velocity of the train be v m/s. 

∴ Relative Velocity = Speed of the train + Speed of the man
  = v + 1.38 

∵ Relative Velocity = Length of the Train/Time taken
v + 1.38 = 100/7.2 

⇒ 7.2v + 9.936 = 100
⇒ 7.2v = 90.064
∴ v = 12.5 m/s.  = 45.03 km/hr. 


Hence the velocity of the train is  12.5 m/s or 45.03 km/hr. 


Hope it helps.
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