Unit Blog Reflection

Unit Blog Reflection

This unit I learned a lot about things that spin around, such as their angular momentum, which is the quotient of the rotational inertia and the rotational velocity.  Rotational inertia is the “laziness” of a rotating object, or it’s resistance to being spun faster or slower.  If something has a lower rotational inertia, but the same energy as something with equal mass, it will spin faster even if they both started with the same rotational velocity.  Rotational velocity, meanwhile, is how fast something is spinning, and is directly influenced by rotational inertia.  The angular momentum will be the same regardless of whether the object is spinning quickly with a low rotational inertia, or if the object is spinning slowly with a high rotational inertia.  I also learned about the different kinds of velocities when an abject is spinning.  Rotational velocity is one of them, but there is also tangential velocity, and they are very different.  For example, if two gears, one small and with 10 teeth, and the other one large and with 20 teeth, are interlocked and spinning together at a rate in which the larger one spins once per second, they will have the same tangential velocities, because they are both spinning at a rate of 20 teeth per second, even though that is two rotations for one of them and one rotation for the other.  However, because one of them has to spin twice as fast to have the same tangential velocity, it therefore has a higher rotational velocity.  We also learned about torque, specifically the effect torque has on your center of gravity and the amount of force you can apply to an object.