A block of iron has dimensions 2 m x 0.5 m x 0.25 m. The density of iron is 7.8 g cm^-3. Find the mass of the block.

The mass of a lead piece is 115 g. When it is immersed into a measuring cylinder, the water level rises from 20 mL mark to 30 mL mark. Find:

(i) the volume of the lead piece,

(ii) the density of the lead 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

How long a train will take to travel a distance of 200 km with a speed of 60 km h^-1?