Aplanet's density can be measured by combining

a. doppler and transit observations.
b. direct imaging from the new generation of space telescopes.
c. spectral observations of the planet's atmosphere.
d. any method that measures the gravitational tug of the planet on the star.
e. doppler and astrometric observations.

Hydrogen and helium are both members of?

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?

Consider a u-tube whose arms are open to the atmosphere. now equal volumes of water and light oil (ρ = 49.3 lbm/ft3) are poured from different arms. a person blows from the oil side of the u-tube until the contact surface of the two fluids moves to the bottom of the u-tube, and therefore, the liquid levels in the two arms are the same. if the fluid height in each arm is 30 in, determine the gage pressure exerted by the person on the oil by blowing.