What does an astronomer mean by "the universe"

You can comfortably hold your fingers close beside a candle flame, but not very close above the flame. why? challenge (optional) : why do candle flames quickly snuff out in gravity-free regions?

When the total amount of a quantity is the same before and after some event occurs, we say that the quantity is (blank)

How do the respiratory, circulatory, digestive and nervous systems work together to get essential materials to the cells of the body

A police siren sounds different as it comes close to you than when it moves away from you. what term explains how this happens? a. diffraction b. the doppler effect c. rarefaction d. shockwaves

A baseball that is falling towards earth has?

if light travels in a vacuum at 3.00 x 10^8m/s and its frequency is 7.44 x 10^7 what is its wavelength

the half-life of carbon - 14 is 5730 years. What fraction of carbon-14 would remain after 11,460 years?

An object with a mass of 10.9 kg experiences a force of 18.53 N. What is the acceleration of the object? A. 2.2 m/s2 B. 1.7 m/s2 C. 16.83 m/s2 D. 1.3 m/s2

A proton, starting from rest, accelerates through a potential difference of 1.0 kV and then moves into a magnetic field of 0.040 T at a right angle to the field. What is the radius of the proton's resulting orbit

Which of the following terms are needed to completely describe speed? Check all that apply. A. Units B. Direction C. Number D. Mass