Work is already done, can someone check if i did the graph right?

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

What are two different ways you could find the value of a? explain these methods.

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.