Answer:
d. 50 C
Explanation:
In this problem, we have to add 800 ml of water at 20 Celsius to 800 ml of water at 80 Celsius.
According to the 2nd law of thermodynamics, heat transfers from hot to cold temperature.
The quantity of both the different waters is equal so this makes it very easy. All we have to do is find the mean of both the temperatures:
Final temperature = (20 C + 80 C)/2
= 50 Celsius
Beginning when the bottom of the object first touches the water,
and as it descends and more and more of it goes under, the
buoyant force on it increases during that time.
As soon as the object is completely underwater, it doesn't matter
how deep under it is, the buoyant force on it remains the same.
To find the total number of miles traveled by a person, we add the distance that he has traveled: 3.0 + 5.00 + 4.000.
Now, to find the accurate number of significant figures when adding measurements, the basic rule for addition is to use the least number of decimal places when reporting the result.
Now, since 3.0 has the least number of decimal places, we report the sum with 1 decimal place and have 12.0 miles as the total distance traveled by the person to reach his destination.
Answer: 12.0 miles