A boy travels with a speed of 10 m s^-1 for 30 minute. How much distance does he travel?

The density of copper is 8.9 g cm^-3. What will be its density in kg m^-3?

A car travels a distance of 15 km in 20 minute. Find the speed of the car in:

(i) km h^-1

(ii) m s^-1

Express 36 km h^-1 in m s^-1.