keitanako
Newest questions and responses by keitanako
astronomy
If the planet is in an edgeon orbit, what would its mass be (in kg)?
asked on June 25, 2014 
astronomy
Hydrogen accounts for 71% of the Sun's mass today. If only one tenth of that Hydrogen burns into Helium, how long could the Sun keep shining at its present luminosity? Note that Hydrogen fusion has an efficiency of about 0.7% Time in years:
asked on May 14, 2014 
Astronomy
Put the following in order from earliest to latest. In doing so, assume that the Nice model occurred as described and that the Grand Tack model also occurred as described. 1) The formation of Jupiter 2) The inward migration of Jupiter due to gas forces 3)
asked on May 13, 2014 
science
How many DALYs are lost by a person who has a life expectancy of 74, contracts HIV/AIDS at the age of 40 and lives until the age of 60? This person receives antiretroviral medication two years after she/he contracts HIV/AIDS until she/he dies. [The
asked on May 5, 2014 
astronomy
Rank the following hypothetical planets  all of which have the same total mass and same radius  from lowest moment of inertia to highest moment of inertia: 1) A uniform sphere of mixed up rock and iron 2) A rocky planet with an iron core 3) A rocky
asked on April 14, 2014 
astronomy
Imagine that you live in a distant galaxy far far away. This galaxy is in a different universe, and so may have different cosmology. It seems that in this distant universe, all galaxies have the same luminosity, which you have worked out is 7.0*10^30 W.
asked on April 11, 2014 
astronomy
Before Dark Energy could be discovered, several preconditions needed to be in place. Tick all the factors below which were necessary for the discovery of dark energy. 1. Large format detectors for wide field imaging 2. Radio interferometers 3. Large
asked on April 11, 2014 
Astronomy
Another star cluster ("star cluster 2") lies 7.4 Megaparsecs from the starship, and has an apparent radius of 6.3 arc seconds. You would like to know how big it is. Is it the same size as galaxies in our universe (i.e. tens of kiloparsecs) or only as big
asked on April 2, 2014 
statistics
The highest point in the scatter is the point for Illinois, at 1807. The two just below it, at 1778 and 1777, are for Minnesota and Iowa. The lowest points are at 1391 and 1385, for Maine and D.C. respectively. Pick all the options that are correct. The
asked on March 22, 2014 
Chemistry
Last week we drew Lewis dot structures of azide (N31), a crucial component in automobile collision safety airbags. During an impact, a sensor ignites a detonator cap that sets off the following rapid reaction: 2NaN3(s) â†’ 2Na(s) + 3N2(g) Part A What
asked on March 19, 2014 
Chemistry
A 10.00 gram solid sample consisting of a mixture of sodium chloride and potassium sulfate is dissolved in 100.0 mL of water is combined with another 200.0 mL solution that contains excess aqueous lead(II) nitrate. Upon mixing the two solutions, a solid
asked on March 18, 2014 
Chemistry
2NaN3(s) > 2Na(s) + 3N2(g) What mass of sodium azide should be loaded in the device to ensure full inflation of the same air bag if the actual reaction can be expected to proceed to give only 83% yield of nitrogen gas?
asked on March 18, 2014 
chemistry
2C3H6(g) + 2NH3(g) + 3O2(g) > 2C3H3N(g) + 6H2O(g) A 150.0 liter steel reactor at 25 ºC is filled with the following partial pressures of reactants: 0.500 MPa C3H6, 0.800 MPa ammonia, and 1.500 MPa oxygen gas. If the reaction proceeds to 90% yield, and no
asked on March 18, 2014 
Chemistry
A 108 mL gas sample has a mass of 77.96 mg at a pressure of 1140 mmHg and a temperature of 183 °C. Assume ideal gas behavior and a completely insulated system, and please donâ€™t forget units with your answers. The system is cooled. Calculate the
asked on March 10, 2014 
Astronomy
Consider dropping a Professor with an estimated mass of 80 kg from a safe, large distance, onto a SMBH with a mass of 10^7MâŠ™. The Prof makes an impact at the Schwarzschild radius, whereby he converts all of the gained kinetic energy into radiation
asked on March 9, 2014 
Astronomy
1. Consider an asteroid of radius 2 km and density 2,500 kg/m^3 impacting the Earth. When it collides with the surface its kinetic energy is, to a large extent, dumped into the environment, some as heat vaporizing rock and some as mechanical energy
asked on December 9, 2013 
Astronomy
The volume of a ball is given in terms of its radius by V=(4*pi/3)*R^3. Use this to find the average density of Nursat, i.e. the mass per unit volume. Use Earth'€™s mass in kg from the Table of Constants to express your answer in kg/m3.
asked on December 9, 2013 
Astronomy
1. At opposition, Nursat(is observed to be in opposition every 374 days.) is observed to subtend an angular radius of 7.1523 arcseconds. Use this and the conversion factors in our Table of Constants to find the radius of Nursat in km. 2. Nursat has a moon,
asked on December 9, 2013 
Astronomy
1. In this collection of problems we will try to use what we have learned to see what information about a hypothetical Solar System planet we can extract from observations. The planet, Nursat, is observed to be in opposition every 374 days. Use this
asked on December 9, 2013 
Astronomy
For an object of mass m in a circular orbit of radius R under the gravitational influence of a center of mass M, find an expression for the total energy, the sum of kinetic and potential energy (with potential energy at infinite distance set to zero), in
asked on December 9, 2013 
Astronomy
A possible trajectory for sending a spacecraft to Mars is an elliptical orbit with Earth at its perihelion and Mars at its aphelion. The craft would be launched out of lowEarth orbit by a quick burst of rockets into solar orbit, and would then "coast''
asked on December 9, 2013 
Astronomy
In fact, more precise calculations suggest that ISON was on a hyperbolic, unbound orbit. How much more precise? Find the minimal speed with which the comet would have had to be moving when observed at perihelion in order to eventually escape the Solar
asked on December 9, 2013 
Astronomy
1. Sungrazing comet ISON disintegrated on November, 2013. Observation of the comet suggested an elliptical orbit with period 581,480 years. What would this predict for the distance from the Sun at the orbitâ€™s aphelion, the farthest point from the
asked on December 9, 2013 
Physics(Help!!!!!!)
A stick of length l = 65.0 cm rests against a wall. The coefficient of static friction between stick and the wall and between the stick and the floor are equal. The stick will slip off the wall if placed at an angle greater than Î¸ = 39.0 degrees. What
asked on December 9, 2013 
Physics(Help!!!!)
A person of mass m2= 85.0 kg is standing on a rung, one third of the way up a ladder of length d= 3.0 m. The mass of the ladder is m1= 15.0 kg, uniformly distributed. The ladder is initially inclined at an angle Î¸= 35.0âˆ˜ with respect to the
asked on December 9, 2013 
Physics(URGENT!!!!)
A ruler stands vertically against a wall. It is given a tiny impulse at Î¸=0âˆ˜ such that it starts falling down under the influence of gravity. You can consider that the initial angular velocity is very small so that Ï‰(Î¸=0âˆ˜)=0. The ruler
asked on December 9, 2013 
Astronomy
1. Imagine that the Earth¡¦s spin were to be reversed, so that the planet rotated about its axis from East to West, at the same rate at which it now rotates from West to East. If Earth¡¦s orbital motion about the Sun were unchanged, which of these
asked on December 5, 2013 
Astronomy
Star Right Ascension Declination Aldebaran 4h 36m 16¢X 31' Miaplacidus 9h 13m 69¢X 42' Deneb 20h 41m 45¢X 20' Regulus 10h 08m 12¢X 18' Hadar 14h 04m 60¢X 24' 1.If Aldebaran is crossing your local meridian, how long would you need to wait to see
asked on December 5, 2013 
Physics(IMPORTANT)
An object of mass m=80 kg moves in one dimension subject to the potential energy U(x)=(Î»/4)(x^2a^2)^2+(b/2)x^2 Here we use Î»=3kg/(m^2s^2), a=7m, and b=77kg/s^2. (b) Find a stable equilibrium point x0 such that x0 is positive. (in meters) x0= (c) Do
asked on November 1, 2013 
Physics(IMPORTANT)
A block of mass m = 2 kg on a horizontal surface is connected to a spring connected to a wall (see figure). The spring has a spring constant k =10 N/m. The static friction coefficient between the block and the surface is mÎ¼s =0.7 , and the kinetic
asked on November 1, 2013 
Physics(IMPORTANT)
An airliner makes an emergency landing with its nose wheel locked in a position perpendicular to its normal rolling position. The forces acting to stop the airliner arise from friction due to the wheels and from the breaking effort of the engines in
asked on November 1, 2013 
Physics(IMPORTANT)
A small ball of mass m=0.60 kg hangs from a massless string of length l=0.9 m. The ball travels in a vertical circle and its speed at the bottom is v0=6.0 m/s (see figure). Neglect all friction and air drag, and use g=10m/s^2 for the gravitational
asked on November 1, 2013 
Physics(IMPORTANT)
A small object of mass m= 90 kg slides down a spherical dome of radius R=12 m without any friction. It starts off at the top (polar angle Î¸=0) at zero speed. Use g=10 m/s2. (See figure) (a) What is the magnitude of the force (in Newtons) exerted by the
asked on November 1, 2013 
Physics(IMPORTANT)
Two skaters of mass m1=50kg and m2=70kg are standing motionless on a horizontal ice surface. They are initially a distance L=7.0 meters apart. They hold a massless rope between them. After pulling the rope, the skater of mass m1 has moved a distance l=2.0
asked on November 1, 2013 
Physics(IMPORTANT)
A meteorite of mass 1*10^4kg is approaching headon a planet of mass 5*10^29kg and radius 5*10^4km. Assume that the meteorite is initially at a very large distance from the planet where it has a speed 3*10^2km/s. Take 6.67*10^11. Determine the speed of
asked on November 1, 2013

astronomy
unanswered
posted on April 11, 2014 
statistics
the answer is wrong...
posted on March 23, 2014 
Chemistry
Thank you, I know how to do it.
posted on March 19, 2014 
Chemistry
Hi, Bob. But how to get (MMPbCl2/2*MMNaCl) and (MMPbSO4/MMK2SO4). Because it is confusing to me. Can you show the step more clearly. Thank you? I just can do step 1, which is X=10Y. But step 2, it is bit confused. I can't get the meaning.
posted on March 19, 2014 
Chemistry
Sorry, I have forgotten to give the information. This question has part a, which is "What mass of sodium azide must be completely reacted to inflate an air bag to 65.0 liters at 20.0 ºC and 1.06 atm?" Please help me because I have calculated many time,
posted on March 19, 2014 
Classical Mechanics Physics  Urgent help please
After finding f_x, use that value in the equation Torque=I_cm *alpha equation (containing F_y and F_x), i think you don't need to find a_y. May I ask how to apply to the equation, please?
posted on December 9, 2013