2.  When a sphere or a cylinder rolls on a flat surface, if there is no friction, the body will experience purely rotational motion.         True

Blocks A and B have a masses of 150 kg and 280 kg, respectively. (Figure 2) The coefficient of static friction between A and B and between B and C is 0.290. The coefficient of static friction between the rope and peg E is 0.570. Pulley D rotates freely, and P = 27.0 N. If \theta = 60.0 degrees, what is the smallest magnitude, T, of tension, T, that causes block B to move? P A B E T

A cast iron flywheel with a mean rim radius of 9 inches is rotated at a speed of 800 rpm. If the weight of the rim is 20 lbs, what is the centrifugal force?

I am working on a Friction lab for my physics class, I will attach my data and graphs. My experimental coefficient of kinetic friction is 4.375, which gives me a minimum angle (theta) = 77 degrees, which is really far off (experimentally 9.5 degrees).  Have I done something incorrectly?  The data is from my instructor (through a video).  Thank you.

Figure 2 В A Block A is hanging from a massless string which runs over a massless and frictionless pulley and connects to Block B. Block B slides over an inclined plane with ordinary kinetic friction. The plane under block B is inclined at an angle theta = 0 away from vertical. The other side of Block B is connected to another massless string which runs over another massless and frictionless pulley to connect to Cart C. Cart C rolls without friction over a plane which is inclined at an angle of phi = y away from vertical. C

5. There is a small amount of friction in the bearings of the pulley wheel. Suggest a way to measure this friction force (in grams).