What is apparent weight, explain relation between apparent weight and actual weight when lift is falling freely.

A block of wood having a mass $15 \mathrm{kg}$ and dimensions $40\mathrm{cm} \times 30\mathrm{cm} \times 20 \mathrm{cm}$ is kept on a table-top, It is made to lie on the table-top in three ways with its sides of dimensions

(a) $40 \mathrm{cm} \times 30 \mathrm{cm}$

(b) $30 \mathrm{cm} \times 20 \mathrm{cm}$

(c) $20 \mathrm{cm} \times 40 \mathrm{cm}$
 

The pressure exerted by the wooden block on the table-top will be

Give reasons: A body experiences more buoyant force on the earth than on the moon.

State whether upthrust will increase or decrease if the volume of the solid increases.

Give reasons: It is easier to swim in the sea than in the river.