Question

A railway car of mass 20 tonnes moves with an initial speed of 54km/hr. On applying brakes, a constant negative acceleration of 0.3m/s2 is produced. (i) What is the breaking force acting on the car? (ii) In what time it will stop? (iii) What distance will be covered by the car before if finally stops?​

Answer 1

Hey,

(i) Friction

(ii)Time=Speed/ acceleration

54km/h=15m/s

=15m/s / 0.3m/s2

Time =50s

(iii)Distance=Speed*Time

50s=0.83m=0.138h

=54*0.138

7.4km

HOPE IT HELPS...........................