Suppose a teenager on her bicycle. The rear wheel is spinning at an angular velocity of 281.133 rpm. She stops it in 3.686 s. How many revolution did it take to stop it?

Explanation:

The formula for angular velocity is

where omega is the angular velocity, theta is the change in the angular rotation, and t is the time in seconds. First and foremost, we have the angular rotation in minutes and the time in seconds, so that's a problem we have to amend. Let's change the angular rotation to rotations per second:

Now we're ready to set up the problem:

and we multiply both sides by 3.686 to get the rotations per seconds:

θ = 17.27 rotations

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000