A room has length 16 m, breadth 12m and height 10 m. The air pressure inside the entire room is 100 k Pa. Find the force exerted by air on the (i) floor (ii) sides of the room.

Answer

(i) `1.92 xx 10^7 N` (ii) `5.60 xx 10^7 N`

Explanation

Here, L = 16m , b =12 m, h = 10 m , `P = 100 k Pa = 100 xx 10^3 Pa = 10^5 Pa,`
(i) Area of floor, A = L xx b = 16xx12 sq. m. Fore exerted by air on floor, `F = PA = 10^5 xx 16xx12 = 1.92 xx 10^7 N` (ii) Area of the walls of the room `A' = (Lxxh + bxxh) 2 =2h(L+b)`
`=2xx10(16+12) = 2xx10xx28 = 560^2` Force exerted by air on walls of room `F' = P' A' =10^5 xx 560 =5.6 xx 10^7 N`