To solve this we are going to use a conversion factor. We know that 1 BTU per hour is approximately 778 foot-pounds of energy per hour, so our conversion factor will be:

.
Now we just need to multiply <span>4000 BTU by our conversion factor:
</span>

<span>
We can conclude that the furnace released </span><span>
3,112,000 foot pounds of energy in one hour.</span>
Answer:
Step-by-step explanation:

Answer:

Step-by-step explanation:
The reference angle is an acute angle that angle in standard position makes with the positive x-axis.
The given angle in radians is

This angle is already acute and hence it is itself a reference angle.
The reference angle of any angle in the first quadrant is the same angle.