When a lunar module landed on the moon, it used thrusters to slow its descent to the surface. when other spacecraft are returned to earth, they use parachutes to slow their descent. why wouldn't a parachute be useful on the moon?

How would a small bar magnet be oriented when placed at position x?

Nitrogen (n2) undergoes an internally reversible process from 6 bar, 247°c during which pν1.2 = constant. the initial volume is 0.1 m3 and the work for the process is 121.14 kj. assuming ideal gas behavior, and neglecting kinetic and potential energy effects, determine heat transfer, in kj, and the entropy change, in kj/s. show the process on a t-s diagram.

The horizontal blue line through the middle of the lens is called the optical axis. as the lamp is moved above or below the axis, keeping the horizontal distance to the center of the lens constant, how does the horizontal distance from the lens to the image change?