Question

A slice of bread contains about 100 kcal. If specific heat of a person were 1.00 kcal/kg·°C, by how many °C would the temperature of a 70.0-kg person increase if all the energy in the bread were converted to heat?a. 2.25°Cb. 1.86°Cc. 1.43°Cd. 1.00°C

Answer 1

Answer:

(c) 1.43°C

Explanation:

If the energy in the bread are converted to heat.

Then, The heat transferred from the bread to person = 100 kcal.

From specific heat capacity,

Q = cmΔT............................ equation 1

Where Q = quantity of heat, m = mass of the person, c = specific heat capacity of the person, Δ = increase in temperature.

Making ΔT the subject the equation 1,

ΔT = Q/cm........................ equation 2

Where Q = 100 kcal, c= 1.00 kcal/kg.°C, m = 70.0 kg

Substituting these values into equation 2,

ΔT = 100/(1×70)

ΔT = 100/70

ΔT = 1.428

ΔT ≈ 1.43°C

The increase in temperature of the body is = 1.43°C

The right option is (c) 1.43°C