Answer:
A.46.7mph
B.50mph
Explanation:
We know that from the data given
Julie drove 50 miles at a speed of 38 mph, and another 50 miles for 62mph. Thus , for the first 50 miles, she drove for the following time
T1= distance/speed
====> 50/38= 1.3hrs
the next 50 miles, she drove for
T2= 50/62
= 0.8hrs
So average speed is
Totaldistance/ total time
100/2.1
= 46.7mph
B. Because the time she used driving at 35 mph is the same amount of time she used driving at 65 mph, the average speed is just the average of the two speeds given which is
(50+50)/2 = 50mph
Explanation:
Because they burn fossil fuels, and in this process large amounts of polluting gases (such as carbon dioxide, sulphure dioxides, nitrogen oxides) are released into the atmosphere. Carbon dioxide is especially problematic, because it is a greenhous gas: most of it cannot be re-absorbed by natural processes therefore increasing the global warming effect.