What role does heat play in the formation of convection currents? Choose the correct answer.

A. When water loses heat, it becomes denser and sinks.

B. When water gains heat, it becomes denser and sinks.

C. When water loses heat to cooler water, the cooler water becomes denser and sinks.

D. When water gains heat, it dissolves more solids and gases, becomes denser, and sinks.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.

Afull journal bearing has a journal diameter of 27 mm, with a unilateral tolerance of -0.028 mm. the bushing bore has a diameter of 27.028 mm and a unilateral tolerance of 0.04 mm. the l/d ratio is 0.5. the load is 1.3 kn and the journal runs at 1200 rev/min. if the average viscosity is 50 mpa-s, find the minimum film thickness, the power loss, and the side flow for the minimum clearance assembly.