On a long horizontally moving belt, a child runs to and fro with a speed 9 km h""^(-1) (with respect to the belt) between his father and mother located 50 m apart. The belt moves with speed of 4 km h""^(-1). For an observer on a stationary platform, the speed of the child runing in the direction of motion of the belt is

On a long horizontally moving belt, a child runs to and fro with a spe

1.	On a long horizontally moving belt, a child runs to and fro with a speed 9 km h""^(-1) (with respect to the belt) between his father and mother located 50 m apart. The belt moves with speed of 4 km h""^(-1). For an observer on a stationary platform, the speed of the child runing in the direction of motion of the belt is
Answer» `4km H^(-1)` `5km h^(-1)` `9 KM h^(-1)` `13 km h^(-1)` ANSWER :D