Question

Just a few questions from a review packet i'm stuck on, anyhelpwould be appreciated!

1) The moment of inertia about its axis is given as .5 mr^2. Ifthiscylinder rolls without slipping the ratio of it's rotationalkineticenergy to it's translational kinetic energy is
a. 2:1
b. 1:1
c. 1:2
d. 1:3

2) An object’s angular momentum changes by 20 kg,m2/s in 4.0s. Whatmagnitude average torque acted on this object?
A. 2.5 N’m
B. 5.0 N-m
C. 40 N-m
D. 80 N’m

3) A solid cylinder of mass 10 kg is pivoted about africtionlessaxis thought the center O. A rope wrapped around theouter radiusR1 = 1.0 m, exerts a force F1 = 5.0 N to the right. Asecond ropewrapped around another section of radius R2 = 0.50 mexerts a forceF2 = 6.0 N downward. (See Fig. 8-1.) What is theangularacceleration of the cylinder?
A) 1.0 rad/s2
B) 0.60 rad/s2 >my guess<
C) 0.40 rad/s2
D) 0.80 rad/s2

4) A solid sphere of mass 1.0 kg and radius 0.010 m starts fromrestand rolls without slipping down a 1.0-m high inclined plane.What isthe speed of the sphere when it reaches the bottom of theinclinedplane?
A) 3.7 m/s >My guess<
B) 4.4 m/s
C) 5.6 m/s
D) 6.3 m/s

5)A railroad car with a mass of 200 kg is going at 10 m/s. A 70kgstunt man drops directly down on it from a distance of 4 mabove.What is the speed of the railroad car after?
a. 4.7 m/s
b. 7.4 m/s
c. 2.8 m/s
d. 10 m/s

6) A projectile is launched with an initial velocity of 60 m/s atanagnle of 30 degrees above the horizontal. How far will itgo?
a. 318 m
b. 160 m
c. 152 m
d. 184 m