On a popular amusement park ride, the riders stand along the inside wall of a large cylinder with a diameter of 8.27 m. the cylinder rotates and when it reaches a rotational frequency of 0.66 revolutions per second the floor drops out. what is the minimum coefficient of static friction needed between a rider and the cylinder wall to prevent the rider from moving down?

Explanation:

D = 8.27 m   ⇒  R = D / 2 = 8.27 m / 2 = 4.135 m

ω = 0.66 rev/sec = (0.66 rev/sec)*(2π rad/1 rev) = 4.1469 rad/s

We can apply the equation

Ff = W  ⇒  μ*N = m*g   (I)

then we have

N = Fc = m*ac = m*(ω²*R)

Returning to the equation I

μ*N = m*g    ⇒    μ*m*ω²*R = m*g   ⇒ μ = g / (ω²*R)

Finally

μ = (9.81 m/s²) / ((4.1469 rad/s)²*4.135 m) = 0.1379

yes !!

Explanation:

Magnets can be found in the simplest or most complex devices you use every day. From home appliances such as the refrigerator, microwave oven and electric fan, to your company's office equipment such as computers and printers. All these devices use magnets.