# Physics Problems

Help me study for my Physics class. I’m stuck and don’t understand.

1. The angular position of a point on a rotating wheel is given by θ = 7.76 + 8.36t2 + 1.80t3, where θ is in radians and t is in seconds. At t = 0, what are (a) the point’s angular position and (b) its angular velocity? (c) What is its angular velocity at t = 4.82 s? (d) Calculate its angular acceleration at t = 2.46 s. (e) Is its angular acceleration constant?

2. A disk rotates about its central axis starting from rest and accelerates with constant angular acceleration. At one time it is rotating at

6.30 rev/s
; 40.0 revolutions later, its angular speed is

22.0 rev/s
. Calculate (a) the angular acceleration (rev/s2), (b) the time required to complete the 40.0 revolutions, (c) the time required to reach the

6.30 rev/s
angular speed, and (d) the number of revolutions from rest until the time the disk reaches the

6.30 rev/s
angular speed.

3. A flywheel with a diameter of 2.42 m is rotating at an angular speed of 114 rev/min. (a) What is the angular speed of the flywheel in radians per second? (b) What is the linear speed of a point on the rim of the flywheel? (c) What constant angular acceleration (in revolutions per minute-squared) will increase the wheel’s angular speed to 1170 rev/min in 123 s? (d) How many revolutions does the wheel make during that 123 s?

4. A gyroscope flywheel of radius

2.59 cm
is accelerated from rest at