A coin rests 12.0 cm from the center of a turntable. The coefficient of static friction between the coin and turntable surface is 0.440. The turntable starts from rest at  t = 0  and rotates with a constant angular acceleration of 0.640 rad/s2. (a) Once the turntable starts to rotate, what force causes the centripetal acceleration when the coin is stationary relative to the turntable? Under what condition does the coin begin to move relative to the turntable?   (b) After what period of time will the coin start to slip on the turntable?

An ultracentrifuge accelerates from to 100,000 rpm in 2.00 min. (a) What is the average angular acceleration in rad/s2 ? (b) What is the tangential acceleration of a point 9.50 cm from the axis of rotation? (c) What is the centripetal acceleration in m/s2 and multiples of g of this point at full rpm? (d) What is the total distance travelled by a point 9.5 cm from the axis of totation of the ultracentrifuge?

Why is the following situation impossible? A space station shaped like a giant wheel has a radius of r = 100 m and a moment of inertia of 5.00 108 kg m2. A crew of 150 people of average mass 65.0 kg is living on the rim, and the stations rotation causes the crew to experience an apparent free-fall acceleration of g (Fig. P10.52). A research technician is assigned to perform an experiment in which a ball is dropped at the rim of the station every 15 minutes and the time interval for the ball to drop a given distance is measured as a test to make sure the apparent value of g is correctly maintained. One evening, 100 average people move to the center of the station for a union meeting. The research technician, who has already been performing his experiment for an hour before the meeting, is disappointed that he cannot attend the meeting, and his mood sours even further by his boring experiment in which every time interval for the dropped ball is identical for the entire evening.

Consider an object on a rotating disk a distance r from its center, held in place on the disk by static friction. Which of the following statements is not true concerning this object? (a) If the angular speed is constant, the object must have constant tangential speed. (b) If the angular speed is constant, the object is not accelerated. (c) The object has a tangential acceleration only if the disk has an angular acceleration. (d) If the disk has an angular acceleration, the object has both a centripetal acceleration and a tangential acceleration. (e) The object always has a centripetal acceleration except when the angular speed is zero.

The propeller of an aircraft accelerates from rest with an angular acceleration = 4t + 6, where is in rad/s2 and t isin seconds. What is the angle in radians through which thepropeller rotates from t = 1.00 s to t = 6.00 s?

A coin rests 15.0 cm from the center of a turn-table. The coefficient of static friction between the coin and turntable surface is 0.350.  The turntable starts from rest at t = 0 and rotates with a constant angular acceleration of 0.730 rad/s2.  (A) Once the turntable starts to rotate, what force causes the centripetal acceleration when the coin is stationary relative to the turntable? Under what condition does the coin begin to move relative to the turntable? (B) After what period of time will the coin start to slip on the turntable?

A coin rests 15.8 cm from the center of a turntable. The coefficient of static friction between the coin and turntable surface is 0.350. The turntable starts from rest at t = 0 and rotates with a constant angular acceleration of 0.622 rad/s2. (a) Once the turntable starts to rotate, what force causes the centripetal acceleration when the coin is stationary relative to the turntable? Under what condition does the coin begin to move relative to the turntable? the static friction causes the cenripetal acceleration (b) After what period of time will the coin start to slip on the turntable? 6.55

A wheel of a radius 5.02 m rotates at a uniform speed. If a point on the rim of the wheel has a centripetal acceleration of 4.00 m/s2, what is the point’s tangential speed?

An advertisement claims that a centrifuge takes up only 0.127 m of bench space but can produce a radial acceleration of 2700 gg at 4800 rev/min. Calculate the required radius of the centrifuge. Express your answer in meters. Is the claim realistic?

A horizontal merry-go-round is initially at rest. At t = 0, it is given a constant angular acceleration ? = 0.0710 rad/s2, which increases its angular velocity. A 23.5 kg child sits at 2.35 m from the axis of rotation.   (a) At t = 9.70 s, determine the centripetal force acting on the child. ________  N   (b) At t = 9.70 s, determine the direction of the net force acting on the child. Specify the angle from the radially inward direction.  ________ °   (c) Through how many radians has the merry-go-round rotated within that 9.70 s time?   _______ rad