(a) The volume of a cube of side 1 cm is given by, V=(1cm)3
or V= (10−2m )3=10−6 m3.
(b) The surface area of a solid cylinder of radius r and height h is givenby :
A= Area of two caps + curved surface area
=2πr2+2πrh=2πr(r+h)
here r=2cm=20mm,
h=10cm=100mm
∴ A=2×

22

7

×20(20+100) mm2
=15086 mm2
=1.5086×104mm2
=1.5×104 mm2
(c) Here v=18 km h−1
=

18×1000 m

3600 s

=5ms−1
t=1 s,x=vt=5×1=5 m
(d) Relative density of lead = 11.3, density of water = 1 g cm‌–3
We know that relative density of lead =

‌density‌of‌lead

density‌of‌water

∴ density of lead = relative density of lead × density of water
=11.3×1g cm−3
=11.3g cm−3
Also in S.I. system density of water = 10‌3kg m‌–3
∴ density of lead =11.3×103kg m−3
=1.13×104 kg m−3