Question

How many calories are equal to one BTU? (One calorie = 4.186 J, one BTU = 1 054 J.)

Answer 1

Answer:

Explanation:

Given

1 calorie is equals to 4.186 J

and 1 BTU equals to 1054 J

using unitary method

$1\ calorie \equiv 4.186 J$

$1\ calorie \equiv 4.186 \times 1 J$

and $1\ J \equiv \frac{1}{1054} BTU$

thus   $1\ calorie \equiv 4.186 \times \frac{1}{1054} BTU$

$1\ calorie\ \equiv 0.00397 BTU$

$1\ calorie\ \equiv 397\time 10^{-5} BTU$  

or $BTU=251.88\approx 252 cal$                      

Answer 2

Answer:

option (c)

Explanation:

According to the question

1 BTU = 1054 J

4.186 J = 1 cal

So, 1 J = 1/4.186 cal

So, 1054 J = 1054 / 4.186 cal

                 = 251.8 cal

By rounding off, it is 252 cal

So, 1 BTU = 252 cal