The amount of oil used by a ship traveling at a uniform speed varies jointly with the distance and the square of the speed. The ship uses 30 barrels of oil in traveling 85 miles at 42 mi/h. How many barrels of oil are used when the ship travels 26 miles at 54 mi/h? Round your answer to the nearest tenth of a barrel, if necessary.

Question

superdavesuper · Answer

"The amount of oil used by a ship traveling at a uniform speed varies jointly with the distance and the square of the speed" so

amount of oil = k*distance*speed^2     where k is a constant

then u can use "30 barrels of oil in traveling 85 miles at 42 mi/h" to solve for k.....

anonymous · Answer

15.2?

superdavesuper · Answer

doesnt seem right - would u show me how u get 15.2 plz?

anonymous · Answer

30=k * 85*(42)^2
30 = 149940k 
k = 30/149940 = 3/14994 = 1/4998 
d = 26
s = 54
O = (26•54^2)/4998 ≈ 15.17

superdavesuper · Answer

very good - i made a mistake in my rounding :( ur ans is right! so rounding to the nearest one tenth, it would be 15.2 barrel :)

anonymous · Answer

Thanks

superdavesuper · Answer

welcome n sorry for doubting ur ans at first!