For helium, let’s label the emission wavelengths, λ(nf, ni) where nf and ni are, respectively, the principal quantum numbers of the final and the initial states. calculate the following emission wavelengths: v λ(3,4), λ(4,6), λ(4,7), λ(4,8) and λ(4,9)

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

Unpolarized light of intensity so passes through two sheets of polarizing material whose transmission axes make an angle of 60∘ with each other as shown in the figure. what is the intensity of the transmitted beam, st?

Choose all the answers that apply. our solar system: is in a spiral galaxy no longer includes pluto is made mostly of empty space is in the andromeda galaxy is the only known system that supports life