Converting Btu to J: Troubleshooting Heat Capacity of Water

[phrygian]

Homework Statement

I am just trying to convert Btu to J based on the heat capacity of water and it is not giving me the right answer.

Homework Equations

The Attempt at a Solution

Btu = C(water) * m(1 lb) * dt(1 F)

1 lb = 0.454 kg
1 F = 9/5 K

1 Btu = 4.186 kJ/(kg*K) * .454 kg * (9/5)K = 3.42 kJ < should be 1054 J, what am I doing wrong?

 

[mgb_phys]

Perhaps (5/9) ?

 

[phrygian]

I thought 1 F = 9/5*C + 32?

 

[mgb_phys]

You want the amount of energy to heat the water through 1 fahrenheit so it's c->f

 

[phrygian]

I have the heat capacity of water in kJ/(kg*K) so arent I converting 1 fahrenheit degree to K?

 

[mgb_phys]

You are calculating the energy needed to heat one pound of water through 1 f
So just like you have the amount of kg in a lb (0.454) you also need the amount of c in an 'f' ie 5/9