Ten identical steel balls, each of mass 27 g, are immersed
in a measuring cylinder
containing 20 cm3 of
water.
The
reading of the water level rises
to
50 cm3.
What is the density
of the steel?
A 0.90 g/cm3
B 8.1 g/cm3
C 9.0 g/cm3
D 13.5 g/cm3
Correct Answer: C (9.0 g/cm3)
Explanation: No. of steel balls = 10
Mass
of each steel ball = 27 g
Mass
of 10 steel balls = (27 x 10) g = 270 g
Reading
before the balls are immersed was 20 cm3
Reading
after the balls are immersed is 50 cm3
So,
volume of 10 glass balls = (50-20) cm3 = 30 cm3
Hence
10 steel balls which have a mass of 270 g have a volume of 30 cm3.
So, the density
of steel = (mass / volume) = 270 g / 30 cm3 = 9 g/cm3
