What is the eventual fate of a brown dwarf? A Gravity ultimately "wins" and it becomes a small black hole. B It remains the same forever. C It gradually cools down and becomes ever dimmer. D It becomes ever denser and hotter until it becomes a white dwarf. E It gradually contracts and heats up until nuclear fusion ignites in its interior and it becomes a faint star.

What species absorbs photons in a protostar's outer layers? A H^+ B dust C H_(2) D H E H^-

Most stars are born in clusters containing thousands of stars. A True B False

What property of a molecular cloud does not counteract gravitational contraction? A thermal pressure B turbulent motions C fragmentation D magnetic fields

What is the greatest mass a newborn star can have A 50 solar masses. B a few hundred solar masses. C 10 solar masses. D ) 20 solar masses.

By mass, the interstellar medium in our region of the Milky Way consists of A 50% Hydrogen, 50% Helium. B 70% Hydrogen, 30% Helium. C 70% Hydrogen, 20% Helium, 10% heavier elements. D 50% Hydrogen, 30% Helium, 20% heavier elements. E 70% Hydrogen, 28% Helium, 2% heavier elements.

At what distance does the typical runner achieve maximum velocity? 15 to 20 meters 20 to 30 meters 25 miles per hour 12 meters

Astronomers estimate that new stars form in our galaxy at the rate of about A one per year. B a few (2-3) per year. C 100 per year. D 20-30 per year. E ten per year.

How many planets are in our solar system? Fifteen Six Three Nine

What two kinds of forces influence waves? Select one: restorative and generating forces backwards and forwards forces the force and not the force thermal force and exthermal force

Hot Questions

Saturn is made up of which gases? a Hydrogen b Helium Both A and B d None of the above

A quantum of radiatior has an energy of 2.0 keV. What is its frequency? $(h=6.63x$ $10^{-34}J\cdot s$ and $1eV=1.60\times 10^{-19}J)$ 1) $3.2\times 10^{17}Hz$ 2) $4.8\times 10^{17}Hz$ 3) $6.3\times 10^{17}Hz$ 4) $7.3\times 10^{17}Hz$ 5) $8.5\times 10^{17}Hz$

Inside a freely-falling elevator you would have no weight. gravitational force on you. both of these none of the above

Which of the following does not involve a change of state? A sublimation of dry ice B freezing water C pouring water into a vacuum-insulated bottle D melting ice

Shown below is the decay equation for ${}^{14}C$ Given this equation, what type of decay does an unstable ${}^{14}C$ nucleus undergo? ${}_{6}^{14}C\rightarrow _{5}^{14}N+_{-1}^{0}e$ a) Gamma Decay b) Beta Decay c) Positron Emission d) Alpha Decay e) Electron Capture f) This question is written incorrectly. Choose this for full points and I also assigned an additional try.

Ultraviolet light or sunlight has no effect on nylon slings. True False

Inside a freely-falling elevator your acceleration is zero. weight is zero. gravitational I interaction with Earth is zero. all the above none of the above

How many joules are needed to change the temperature of 1 g of water by $1^{\circ }C$ Express your answer with the appropriate units.

64. Food probe thermometers that display both Fahrenheit and Celsius scales must have an accuracy of $\pm 0.9^{\circ }F(\pm 0.5^{\circ }C)$ $\pm 1.8^{\circ }F(\pm 1^{\circ }C)$ $\pm 2.7^{\circ }F(\pm 1.5^{\circ }C)$ $\pm 3.6^{\circ }F(\pm 2^{\circ }C)$

A golf ball is struck across a flat fairway at an angle of $60^{\circ }$ with an initial speed of $135ft/s$ a.). Write a set of parametric equations for the motion of the golf ball. b.). Determine how long the golf ball was in the air. c.). Determine how far the golf ball traveled in the air. Show all work. Use the Equation Editor. $x=v_{0}cos(\Theta )t$ Recall, $y=-\frac {1}{2}(g)t^{2}+v_{0}sin(\Theta )t+h$ $g=32ft/sec/sec$