If a 0.15 kg ball on the end of a string is swung in a vertical circle of radius .6 meters and makes 2 revolutions per second, what is the tension in the string at the very top of the circle? what is the tension in the string at the bottom of the circle? (12.7 n; 15.7 n)

12.7 N

15.7 N

Explanation:

mass (m) = 0.15 kg

radius (r) = 0.6 m

speed  = 2 rps = 2 x 60 = 120 rpm

acceleration due to gravity (g) = 9.8 m/s^{2}

find the tension at the top and bottom of the circle.

Tension at the top T =

        v =  radius x rpm x 0.10472 = 0.6 x 120 x 0.10472 = 7.54 m/s

         T = = 12.7 N      

Tension at the bottom T' =

        v =  radius x rpm x 0.10472 = 0.6 x 120 x 0.10472 = 7.54 m/s

         T' = = 15.7 N      

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )

change tension