The temperature measured by a weather balloon is decreasing approximately 5° for each 1000-foot increase in altitude.

Question

The temperature measured by a weather balloon is decreasing approximately 5° for each 1000-foot increase in altitude. The balloon rises 8000 feet. What is the total temperature change?

Answer 1

How many 1000-foot increases are there in 8000 feet?

Well, there are 8.

For each 1000-foot increase the temperature decreases 5 degrees, so for 8 of these increases, there is 8 x 5 = 40 degrees drop in temperature.

 

Now using algebra.

We use a proportion to solve this type of question.

Let x = temperature decrease for 8000-foot increase in altitude.

 

Set up a ratio of altitude change / temperature change for each amount and set them equal to each other.

When two ratios are equal, it is called a proportion.

 

1000/5 = 8000/x  

 

cross multiply

 

1000x = 40000

 

x = 40 degrees    which is same answer above