Sound energy cannot travel through
a vacuum, a wooden table, polluted air, pond water

How will each of the following changes in demand and/or supply affect equilibrium price and equilibrium quantity in a competitive market; that is, do price and quantity increase or decrease, or are the answers indeterminate because they depend on the magnitudes of the shifts?

Aplanet of mass m 6.75 x 1024 kg is orbiting in a circular path a star of mass m 2.75 x 1029 kg. the radius of the orbit is r 8.05 x107 km. what is the orbital period (in earth days) of the planet tplanet?

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.