If in an elliptical orbit, rp/ra = 0.5, what is the eccentricity of the orbit?

Which subatomic particle has a negative charge

Abatter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the ball leaves the bat at 40 m/s in the reverse of its original direction. the ball remains in contact with the bat for 2.0 ms. what is the magnitude of the average force exerted by the bat on the ball?

The text compares alternating current with direct current. how are they different? a alternating current reverses direction in the electrical wiring. direct current flows in one direction only. b direct current reverses direction in the electrical wiring. alternating current flows in one direction only. c direct current is powered by solar energy. alternating current is powered by electrical energy. d alternating current does not move in the electrical wiring. direct current does move in the electrical wiring.