Fill in the blanks
(a) The volume of a cube of side 1 cm isk equal to….. `m^3`
(b) the surface area fo a solid cylinder of radius 2.0 cm and height 10.0 cm is equal to …. `(mm)^2`
(c ) A vehical moving with a speed of `18km h^(-1)` covers ....m in 1s.
(d) The relative density of lead is 11.3. its density is ......g `cm^(-3) or .....kg m^(-3)`

Explanation

(a) As length of the side = 1cm
The volume of a cube of side 1 cm is equal to `=1xx1xx1 cm^(3)`.
`=1xx((1)/(100))^(3)m^(3)= 10^(-6)m^(3)`.
(b) Total surface area of a solid cylinder,
`A= 2pir^(2)+2pi rh= 2pi r(r+h)`
`r= 2cm= 20mm, h= 10 cm=100mm`
`A= 2xx(22)/(7)xx20(20+100)`
`=15086 mm^(2)`
`approx 1.5xx10^(4)mm^(2)`.
(c ) `18 kmh^(-1) = (18xx1000)/(60xx60)= 5 ms^(-1)`
The distance covered by the vehicle in 1 second = 5m.
(d) The relative density of lead = 11.3
density `=11.3 gcm^(-3)" or "11300 kgm^(-3)`.
`1g=10^(-3)kg, 1cm= 10^(-2)m`
`11.3gcm^(-3)= 11.3(10^(-3)kg)(10^(-2)m)^(-a)`
`=11.3xx10^(-3)xx10^(8)kgm^(-3)`
`=11.3xxkgm^(-3)= 1.13xx10^(4)kgm^(-3)`.