During the lunar mission of Apollo 11, Armstrong and Aldrin descended to the moon’s surface in the lunar module while Collins remained in orbit in the command module. If the command module’s period was 2 hours and 20 minutes, how high above the moon’s surface did it orbit? (mmoon = 7.35 x 1022 kg, Rmoon = 1.74 x 106 m, and G = 6.67 x 10-11 N m2/kg2)

Which atomic model was proposed as a result of j. j. thomson’s work?

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.