on a long horizontal moving belt child to and fro with a speed of 9 km per hour with respect to the bed between his father and mother located 50 metre apart on a moving belt belt most with a speed of 4 km per hour for an observer on a stationary platform outside what is the. (a) speed of the child running in the direction of the motion of the belt. (b) speed of a child running opposite to the direction of the motion of the belt
Answers
13 km/hr
5 km/hr
Given:
Speed of the Child (w.r.t) belt = 9 km h^-1
Speed of the belt = 4 km hr^-1
\(a) When the child runs in the direction of motion of the belt, then speed of child w.r.t. stationary observer
We calculate using the formula:
Speed of child with respect to the belt + speed of the belt
Substituting the values which we know into this formula we get:
=> (9 + 4)km/hr
=> 13 km/hr
Therefore, the speed when the child runs in the direction of motion of the belt then the speed of the child with respect to the with respect to the stationary observer is 13 km/hr.
(b) When the child runs opposite to the direction of motion of the belt, then speed of child with respect to the stationary observer,
We calculate using the formula:
Speed of the child with respect to the belt - speed of the belt
=> (9 - 4) km/hr
=> 5 km/hr
Therefore, when the child runs opposite to the direction of motion of the belt then the speed of the child with respect to the stationary observer would be 5 km/hr.