Question

A train started from rest and moving with constant acceleration upto 10 sec. After 5 sec its speed become 42 km/h
(1)find acceleration of train (2)speed after 10 sec (3)distance travelled by train in 7 sec and 10 sec respectively

Answer 1

AccelerationxTime=Speed

Acceleration=a

Time=5sec

Speed=42km/hr=>11.66m/s

=>Acceleration=2.33m/s^2---------------Answer(i)

Speed=AccelerationxTime

=>Speed=2.33x10

=>Speed after 10 sec is 23.3m/s-----------------Answer(ii)

S=ut+at^2/2

=>S after 7 sec=0x7+2.33x49/2

=>56.66metres------------------------Answer(iii)

S after 10 sec=0x10+2.33x100/2

=>116.66metres--------------------------Answer(iii)