The interstellar medium is composed of
a. gas and dust
b. asteroids
c. metals and rocks
d. empty space

Two particles of masses m and 2m are placed on a smooth horizontal table. a string, which joins these two masses, hangs over the edge supporting a pulley, which suspends a particle of mass 3m.the pulley has negligible mass. the two parts of the string on the table are parallel and perpendicular to the edge of the table. the hanging parts of the string are vertical. find the acceleration of the particle of mass 3m.

What is the earliest point in the universe that we can observe? why can’t we see back further than this?

Five structural isomers have the formula c6h14. where needed, draw the structure and give the iupac name of all five isomers.