Rotational Motion Exam 1 and Problem Solutions
1. An object, attached to a 0,5m string, does 4 rotation in one second. Find
b) Tangential velocity
c) Angular velocity of the object.
a) If the object does 4 rotation in one second, its frequency becomes; f=4s⁻¹
b) Tangential velocity of the object;
c) Angular velocity of the object
2. Find the relation between tangential and angular velocities of points X, Y and Z. X and Y rotate together, so if X does one rotation then Y also does one rotation. On the contrary, if Y does one revolution, Z does two revolutions. Angular velocities of the X, Y and Z are;
3. An object hanged on a rope L=0,5m, does rotational motion. If the angle between rope and vertical is 37⁰, find the tangential velocity of the object. (g=10m/s², cos37⁰=0,8, sin37⁰=0,6) Free body diagram of system is given below; Horizontal component of tension on the rope makes object rotate.
Radius of the motion path is;
4. An object having mass m does rotational motion. Its angular velocity is ω and radius of motion path is r. Find kinetic energy of the object in terms of r, ω, and m.
5. Stone having mass 0,5kg rotates in horizontal. It is hanged on 1m rope. If the tension on the rope is 80 N, find the frequency of the motion.