How many stars are there in the entire universe?

Quasar spectra often show many absorption lines that all appear to be as a result of the same electron transition (such as level 1 to level 2 in hydrogen) but that fall at different wavelengths in the spectrum. Why do we think this is the case?

A spring has a spring of 120 newtons per meter. calculate the elastic potential energy stored in the spring when it is stretched 2.0 centimeters ...?

25. Which units would be the most appropriate to use to measure the degree of attraction between two objects due to their mass?

How could you separate a mixture of marbles, corks, and nails?

what is force? is it desirable or undesirable?

What is the total number of atoms in the following formula? CaBr2 4 3 2 1

Object A with a mass of 500 kilograms hits stationary object B with a mass of 920 kilograms. If the collision is elastic, what happens after the collision? A) Both object A and object B move forward but with different velocities.

A young man walks daily through a gridded city section to visit his girlfriend, who lives m blocks East and nblocks North of where the young man resides.

Aliens from planet Moby have three alleles for skin color: R (red) W (white) and B (Blue). If all of these alleles are codominant and aliens on planet moby can only inherit two alleles for a gene, what are the six possible genotypes for skin color

The difference between two numbers is 15. When twice the smaller number is subtracted from three times the larger number, the difference is 58. What is the larger number?