I think you should hold a stretch for 10-30 seconds
Answer:
30 miles
Explanation:
<u>Step 1:</u>
Divide -> 45/60= .75 miles/minute
<u>Step 2:</u>
Multiply -> .75 x 40= 30
The efficiency of an ideal Carnot heat engine can be written as:

where

is the temperature of the cold region

is the temperature of the hot region
For the engine in our problem, we have

and

, so the efficiency is
Density=mass÷volume
mass=density×volume
mass=2×8=16 g