Question

The wheels on jason's dirt bike messure 19 inches in diameter. How many revolutions will the wheels make when jason rides for 500 ft? Use 3.14 for pi. Round to the nearest whole number.

Answer 1

Radius 8.5

Circumference 2 pi r^2
=2(3.14)(8.5)^2
=6.28*72.25
= 453.73 in

12in=1ft
(453.73)/12
= 37.81083333333333
≈38

500/38
= 13.15789473684211
≈14

Answer 2

Answer:     101 revolutions

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Explanation:

C = circumference

C = pi*d

C = 3.14*19

C = 59.66

The distance around the wheel's edge is roughly 59.66 inches. This corresponds to the distance the bike travels after the tire spins one full revolution. It might help to imagine that there's wet paint on his tire, and that paint is being transferred to the flat ground.

Let x be the number of revolutions. After those x revolutions happen, the bike has moved forward 59.66x inches. Set this equal to 6000 (because 500 ft = 500*12 = 6000 inches) and solve for x

59.66x = 6000

x = 6000/59.66

x = 100.569896077774

x = 101

After 101 revolutions, Jason has traveled about 500 ft.

Note how x = 100 is too small because 59.66*x = 59.66*100 = 5966 which is 34 inches short of 6000 inches.

And also notice that x = 101 works because 59.66*x = 59.66*101 = 6,025.66 which is over the target mark we're after.