How many Btu of heat must be added to 900lbs of steel to raise its temperature from 20.0°F to 500°F?

Specific heat of steel .115Btu/lb°F

Q= c•m •Δt =0.115•900•480 =49680 Btu

To find out how many Btu of heat must be added to 900 lbs of steel, we can use the formula:

Q = m * c * ΔT

Where:
Q = heat energy (in Btu)
m = mass of the substance (in lbs)
c = specific heat of the substance (in Btu/lb°F)
ΔT = change in temperature (in °F)

Given:
m = 900 lbs
c = 0.115 Btu/lb°F
ΔT = 500°F - 20°F = 480°F

We can substitute the given values into the formula:

Q = 900 * 0.115 * 480

Calculating this, we have:

Q = 49,680 Btu

Therefore, 49,680 Btu of heat must be added to 900 lbs of steel to raise its temperature from 20.0°F to 500°F.