Question

A water tank of dimensions 11m × 6m × 5m is full of water. The tank is emptied through a pipe of

cross section 33 cm2

in 20 hours. Find the rate of water (in kmph).

Answer 1

the volume of the tank = 11×6×5=330
and the length of the pipe will be 330/33/100×1/100
because 1 m=100 cm
100000cm
since 1km= 100000cm
the length of pipe is 1 km
so rate of water or the speed of water is length or distance/time
1/20km/hr
0.05km/hr

Answer 2

The rate of water is 5kmph

Explanation:

Given:

1. A water tank of dimensions 11m × 6m × 5m is full of water.

2. The tank is emptied through a pipe of cross-section 33 cm2 in 20 hours.

To find:

The rate of water

Solution:

==> Volume of water tank = l×b×h

==> Volume of water tank = 11×6×5

==> Volume of water tank = 330m³

We know that 1m = 0.001 km

==> 1m = 10⁻³km

==> 1m³ = 10⁻⁹ km³

==> Volume of water tank = 330×10⁻⁹km³ ==>1

==> The tank is emptied through a pipe of cross-section 33 cm² in 20 hours.

==> Volume of water in 20 hours = 20×v×33cm²

We know that, 1cm = 0.00001 km

==> 1 cm = 1/100000 km

==> 1cm = 10⁻⁵km

==> 1cm² = 10⁻¹⁰ km³

==> Volume of water in 20 hours = 20×v×33×10⁻¹⁰ km³ ==>2

Equate equations 1 and 2  to find v

==> 330×10⁻⁹ = 20×v×33×10⁻¹⁰

==> 10×10⁻⁹ = 20×v×10⁻¹⁰

==> 10⁻⁸ = 2×10×v×10⁻¹⁰

==> 10⁻⁸ = 2×v×10⁻⁹

==> 2v =  10⁻⁸ ×10⁹

==> 2v = 10

==> v = 5 kmph

==> The rate of water is 5kmph