(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××20(20+100) mm2 =15086 mm2 =1.5086×104mm2 =1.5×104 mm2 (c) Here

v=18 km h−1 ==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−3Also in S.I. system density of water = 10

3kg m

–3∴ density of lead

=11.3×103kg m−3=1.13×104 kg m−3