Question

how long does it take a 800W heater to raise the temperature of 20kg of water from 20°C to 60°C given specific heat capacity of water to be 4200j/kgk​

Answer 1

Answer:

it take 70 minutes for a 800W heater to raise the temperature of 20kg of water from 20°C to 60°C

Explanation:

Given,

Power = 800 W

Mass of water = 20 kg

Change in temperature = ΔT = (60 - 20) = 40°C

We know,

Work done = msΔT

power * time = msΔT

800 * t = 20 * 4200 * 40

t = (20 * 4200 * 40) / 800

t = 4200 seconds

or,t = 70 minutes

Therefore, it take 70 minutes for a 800W heater to raise the temperature of 20kg of water from 20°C to 60°C