In a perfectly elastic collision, a 0.400 kg ball moving toward the east at 3.7 m/s suddenly collides head-on with a 0.200 kg ball sitting at rest.

the answer is d

explanation:

dan realized that his goal of going to an ivy league school if only he works hard which means basically this   to become completely aware of (something) as a fact; understand without a doubt to make (something desired or anticipated) occur to give real, definite or physical form to a plan, dream, or goal to earn (money or a profit) from a deal

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

battery with hi vtge high val resist in series