Conversion of m/sec to km/hr

Conversion of km/hr to m/sec

A train passes two persons walking in the same directions at a speed 5 km/hr and 7 km/hr respectively in 10 sec and 11 sec respectively. Find the speed of the train.

A train having speed of 72 km/hr crosses a pole in 18 sec and a platform in 33 sec. Find the length of platform?

A train having speed of 36 km/hr crossing a pole in 15 sec and a platform in 42 sec . Find the length of platform ?

A speeder in an automobile passes a stationary policeman who is hiding behind a bil board with a motorcycle. After a 2.0 sec delay (reaction timwe) the policeman accelerates to his maximum speed of 150km//hr in 12 sec and catches the speeder 1.5km beyond the billboard. find the speed of speeder in km//hr .

A person travels equal distances with speeds of 3 km/hr, 4 km/hr and 5 km/hr and takes a to a time of 47 minutes. The total distance (in km) is 2 b. 3 c. 4 d. 5