When we observe a distant galaxy whose photons have traveled for 10 billion years before reaching earth, we are seeing that galaxy as it was when the universe was?

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

A15.75-g piece of iron absorbs 1086.75 joules of heat energy, and its temperature changes from 25°c to 175°c. what is the specific heat capacity of iron?

The drag force, fd, imposed by the surrounding air on a vehicle moving with velocity v is given by fd = cdaρv 2/2 where cd is a constant called the drag coefficient, a is the projected frontal area of the vehicle, and ρ is the air density. an automobile is moving at v = 80 kilometers per hour with cd = 0.28, a = 2.3 m2, and ρ = 1.2 kg/m3.