The following are practice problems to prepare for a physics exam. Any help would be most appreciated.

2. The rate of rotation for popular music records on a record player was 45 RPM.
a. Express this rotational velocity in rev/s. I
b. Through how many revolutions does the record turn in a time of 5 s? The record turns 3.75 revolutions in 5 seconds.
5*.75=3.75
6. The rotational velocity of a spinning disk decreases from 6 rev/s to 3 rev/s in a time of 12 s. What is the rotational acceleration of the disk?
8. A force of 50 N is applied at the end of a wrench handle that is 24 cm long. The force is applied in a direction perpendicular to the handle as in the diagram.
a. What is the torque applied to the nut by the wrench?
b. What would the torque be if the force were applied half way up the handle instead of at the end?
12. A net torque of 60 N*m is applied to a disk with a rotational inertia of 12.0 kg*m2. What is the rotational acceleration of the disk?