Question

Suppose that 6 people sitting in a enclosed room are each generating about 400 BTUs of body heat per hour. If the room is 20 ft × 15 ft × 10 ft, how many BTUs per cubic foot do they produce in 5 hours? A) 3 BTUs/ft3 B) 4 BTUs/ft3 C) 5 BTUs/ft3 D) 6 BTUs/ft3

Answer 1

Answer: B) 4 BTUs/ft^3

Step-by-step:

For a cuboid of length L, width W and height H, the volume is:

V = L*W*H

In this case, we have:

L = 20ft

W = 15ft

H = 10ft

Then the volume of the room is:

V = 20ft*15ft*10ft = 3000 ft^3

Now we have 6 people, and each generate 400 BTUs per hour.

Then in total, they generate:

6*400 BTUs per hour

2400 BTUs per hour.

Now we want to find the BTUs per ft^3 produced in 5 hours.

Then if they generate 2400 BTUs per hour, in 5 hours they generate a total of:

5*2400 BTUs = 12000 BTUs

Now we take the quotient between the total BTUs and the volume of the room:

Q = (12000 BTUs)/(3000 ft^3) = 4 BTUs/ft^3

The correct option is B.