What is the centripetal acceleration of a point on the perimeter of a bicycle wheel of diameter 70 cm when the bike is moving 8.0 m/s?
2.1 x 10² m/s².
2.7 x 10² m/s².
91 m/s².
1.8 x 10² m/s².
A coin of mass m rests on a turntable a distance r from the axis of rotation. The turntable rotates with a frequency of f. What is the minimum coefficient of static friction between the turntable and the coin if the coin is not to slip?
(4πf2r)/g.
(4πfr2)/g.
(4π2f2r)/g.
(4π2fr2)/g.
A stone, of mass m, is attached to a strong string and whirled in a vertical circle of radius r. At the exact top of the path the tension in the string is 3 times the stone's weight. The stone's speed at this point is given by
2gr.
(gr)1/2.
2(gr)1/2.
(2gr)1/2.
