Question

A  train  of  length  50m  is  moving  with  a  constant  speed  of  lOm/s.  Calculate  the  time
taken  by  the  train  to  cross  an  electric  pole  and  a  bridge  of length  250  m.  

SCERT Class 9 Telangana, Physical Science Ch 2 Motion

Answer 1

to cross an electric pole...
d=50m(length of train...as the whole train has to cross the pole)
s=10m/s
t=d/s=50/10=5seconds
to cross the bridge...
d=50+250=300m(length of train+bridge)
s=10m/s
t=d/s=200/10=20seconds