In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly drops away! If all goes well, the passengers will "stick" to the wall and not slide. Clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. What is the min rotational velocity in revolutions per second for which the ride is safe?

1.25 rev/s

Explanation:

N = mv^2/r (normal force )

f = μN  [Frictional force ]

f = mg

μN = mg

μ(mv^2/r) = mg

v = √(rg/μ)

min rotational velocity

v = √(rg/μ) = √(2.5 * 9.8/0.40) =  7.83 rad/sec

=  7.83/2π =  1.25 rev/s

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

-reverse card

a cold ice-tea.

pour in room temperature or cold water. cover the pitcher and refrigerate. steep white or green tea for 6 to 8 hours; steep black or oolong tea for 8 to 12 hours.jun 28, 2015