Hi, i am glad i have found this site. I am taking an online physics course, the kind where you read the book, work the problems, and take the test. Needless to say it has been very hard on me. I must be really dense at physics because i have purchased supplemental books but to no avail. I have a few questions on rotation and would like to know if i can get a general outline as what to do. I am not posting specific homework problems, but just the general idea of them, so i may work them out myself.(adsbygoogle = window.adsbygoogle || []).push({});

#1. Given a rotation rate in rad/sec and an accelleration rate in rad/sec^2, find:

a. Rotation rate after a given time in seconds

b. Angular displacement in radians during that time.

#2. Someone is slinging a rock of given mass around his head. Knowing the length of the sling and rotation rate find tangetial velocity of mass, centripital acceleration of rock, and tension in rope.

#3. A wheel requires a given number of radians of rotation to accelerate from rest to a given angular rotation rate (in rad/sec). Find angular rate of acceleration, time to accelerate to given rotation rate, rotation rate after x seconds.

#4. A horizontal beam is attached to a frictionless hinge on a wall. Beam weight is given. A weight is placed on the beam at a given location. A VERTICAL cable supports the beam at the outer end. Find

tension in cable

x-component of force exerted on the beam by the wall

y-component of force exerted on the beam by the wall

(that VERTICAL cable is getting me)

#5. A solid disc has a frictiionless axle running through its center, allowing it to rotate about this axis. Radius is given. Find tangetial force required to accelerate the disc from rest to a given rotation rate in a given number of seconds.

These are the main problems i am having. Sorry if these seem somewhat easy to some people, but i do not even know where to start on some of them. Thanks to anyone who helps.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Physics woes - online course - Rotation

**Physics Forums | Science Articles, Homework Help, Discussion**