Tutor profile: Sehej S.

What is the difference between a bushing and a bearing?

Bearings are used to allow a shaft free rotational motion via rolling contacts by bearings. Bushings on the other hand allow free linear motion along a shaft via sliding contact by the bushing on the shaft.

Describe some considerations you would make in designing a heat exchanger to be used downstream of a conventional ramjet (with shock cone) for an aircraft traveling at Mach 5 speeds.

Besides conventional limitations on the rocket equation and vehicle thrust by gross mass: - Rate of heat exchanged between materials varies based on HX geometry, air flow conditions, and working fluid characteristics. - Based on the conditions specified, a large delta bulk temperature between fluids is expected, thus the NTU-effectiveness method is proposed instead of LMTD.

You are given a flat disk and ring with the same thickness, outside diameter, and mass. You set both on a track to fall at a 45deg incline. Which will reach the bottom first and why?

The disk reaches the bottom in nearly half the time it takes the ring. This is because it has half of the moment of inertia (Idisk = 0.5mr^2) vs (Iring = mr^2).