Question

Two tanksAandB contain water at30°and80°respectively.caluculate the amount of water that must be taken from each tank to prepare 40kgof water at50°C.

Answer 1

Explanation:

The amount of water that must be taken from A and B to prepare 40kg water at 50°C is 24kg, 16kg (1).

Let the mass of water taken from tank A be x kg.

Then, the mass of water taken from tank B = 40-x kg.

We know, H=mst,

where m=mass of water, s = specific heat of water and t=temperature change.

Heat absorbed by tank A= xs(50-30) J

Heat released by tank B=(40-x)s(80-50) J

Now,

H_{A}=H_{B}H

A

=H

B

⇒xs(50-30)=(40-x)s(80-50)xs(50−30)=(40−x)s(80−50)

⇒20x=30(40-x)20x=30(40−x)

⇒2x=120-3x2x=120−3x

⇒x=24x=24

Mass of water taken from tank A = 24kg

Mass of water taken from tank B = (40-24) kg = 16kg.