physics helpppp?

Question

How long does it take to heat 125 L of water from 24.7°C to 47.3°C, neglecting conduction and other losses?

Answer 1

This question cannot be answered unless you have some rate of heating or energy transfer.

Assuming you have a rate of energy transfer to the liquid, then the relevant equation for calculating the energy this change in temperature requires is

ΔE = mcΔT (1)

where ΔE is the change in internal energy, m is the mass of the material, ΔT is the change in temperature and c is the mass-specific heat capacity, which is a constant dependent on the material, which specifies the amount of energy required to raise the temperature of a material by 1 Kelvin per unit mass. For water, c ≈ 4184 joules per Kelvin per kilogram (J/K kg).

The mass of the water is given by the relationship

m = ρ V

Where ρ (rho) is the density, m is the mass and V is the volume of the material in question.

For water, ρ ≈ 1000 kg / m³ = 1000 kg / l = 1 tonne / m³

Plugging these numbers into (1), we get ΔE ≈ 11.8 GJ (gigajoules).

All that is needed now is to divide ΔE by the rate of transfer of energy to get the time, t.

Answer 2

Part of the problem is missing. What are the properties of the gismo used to supply heat (calories/time)?

Answer 3

Depends on the amount of heat (energy) supplied.