Please help with physics. 10 points best answer.
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Please help with physics. 10 points best answer.

[From: ] [author: ] [Date: 11-05-31] [Hit: ]
44m/s)*6.8s = 30.distance per revolution = pi*0.119m = .number of revolutions = distance/distance per revolution = 30.19m/.......
The wheels on a bicycle are 11.9 cm in diameter. The bicycle starts from rest and attains a velocity of 32 km/hr in 6.8 seconds. How many revolutions did the back wheel make during the 6.8 seconds?

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Assuming a constant acceleration you can use the average velocity to determine the distance covered but first you must get the velocity in m/s:

average velocity = (16km/hr)*(1hr/60min)*(1min/60s)*(1000m/… 4.44 m/s

distance = velocity*time = (4.44m/s)*6.8s = 30.2m

In one revolution the wheel will cover one circumference of the tire:

distance per revolution = pi*0.119m = .374m

number of revolutions = distance/distance per revolution = 30.19m/.374m = 80.7revolutions

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Assuming constant acceleration, you need to figure out how far the bike went. First use the equation Vf=Vi+a*t Vf=32 Vi=0 t=6.8 solve for a a=4.7 m/s^2

now apply Xf=Xi+Vi*t+1/2*a*t^2 Xi=0 Vi=0 a=4.7 t=6.8 solve and Xf=108.7 m

now we need to know how far the bike goes in 1 rotation. so 100cm=1m 11.9 cm = .119m
The circumference of a wheel is 2*Pi*r or Pi*D.

The distance the wheel travels in 1 rotation is 0.373 m

.373*rotations=108.7

Rotations= 290.7


EDIT: My method is correct, My answer is wrong. I did not realize the Velocity was in km/hr, you need to convert the velocity.
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