Friday
December 2, 2016

# Posts by KS

Total # Posts: 93

Chemistry
The human body is said to contain approximately 50.0 grams of DNA in the entire body. If the number of nucleotides in ONE STRAND of DNA is approximately 3.0 x 106, and the average molar mass of a nucleotide is 327 g/mol, what is the average molar mass of an entire DNA double ...
May 11, 2016

Chemistry
A hot air balloon is filled with hot air and the hot air forces the volume of the balloon to expand until the density of the gas in the balloon is less than the density of the outside air. The volume must be 20% larger than the balloon would be at STP in order for the balloon ...
April 25, 2016

Math
Isaac is packing boxes into a carton that is 12 inches long 18 inches wide and 6 inches high. The boxes are 4 inches long 6 inches wide and 2 inches high. How many boxes will fit inside the carton?
January 6, 2016

PHYSICS
Find the mass of water that vaporizes when 4.04 kg of mercury at 210 °C is added to 0.498 kg of water at 81.6 °C. I am stuck on trying to figure out how to solve this. Please help!
May 20, 2015

PHYSICS
Find the mass of water that vaporizes when 4.04 kg of mercury at 210 °C is added to 0.498 kg of water at 81.6 °C.
May 20, 2015

PHYSICS
A Goodyear blimp typically contains 5040 m3 of helium (He) at an absolute pressure of 1.10 x 105 Pa. The temperature of the helium is 282 K. What is the mass (in kg) of the helium in the blimp?
May 20, 2015

PHYSICS
The drawing shows an ideal gas confined to a cylinder by a massless piston that is attached to an ideal spring. Outside the cylinder is a vacuum. The cross-sectional area of the piston is A = 2.50 × 10-3 m2. The initial pressure, volume, and temperature of the gas are, ...
May 20, 2015

PHYSICS
A thermos contains 152 cm3 of coffee at 93.8 °C. To cool the coffee, you drop two 11.6-g ice cubes into the thermos. The ice cubes are initially at 0 °C and melt completely. What is the final temperature of the coffee in degrees Celsius? Treat the coffee as if it were ...
May 20, 2015

PHYSICS
Find the mass of water that vaporizes when 4.04 kg of mercury at 210 °C is added to 0.498 kg of water at 81.6 °C.
May 18, 2015

PHYSICS
An ice chest at a beach party contains 12 cans of soda at 2.69 °C. Each can of soda has a mass of 0.35 kg and a specific heat capacity of 3800 J/(kg C°). Someone adds a 6.05-kg watermelon at 24.1 °C to the chest. The specific heat capacity of watermelon is nearly ...
May 13, 2015

When some stars use up their fuel, they undergo a catastrophic explosion called a supernova. This explosion blows much or all of a star's mass outward, in the form of a rapidly expanding spherical shell. As a simple model of the supernova process, assume that the star is a...
May 4, 2015

PHYSICS
How do I solve this? The blade of a windshield wiper moves through an angle of 90.0° in 0.453 s. The tip of the blade moves on the arc of a circle that has a radius of 0.775 m. What is the magnitude of the centripetal acceleration of the tip of the blade?
April 26, 2015

PHYSICS
How do I solve this? A mine car (mass=380 kg) rolls at a speed of 0.50 m/s on a horizontal track, as the drawing shows. A 170-kg chunk of coal has a speed of 0.92 m/s when it leaves the chute (at a 25 degree incline). Determine the speed of the car–coal system after the ...
April 26, 2015

PHYSICS
How do I solve this? A 700-kg race car can drive around an unbanked turn at a maximum speed of 41 m/s without slipping. The turn has a radius of 190 m. Air flowing over the car's wing exerts a downward-pointing force (called the downforce) of 12000 N on the car. (a) What ...
April 26, 2015

PHYSICS
How do I solve this? For the normal force in the drawing to have the same magnitude at all points on the vertical track, the stunt driver must adjust the speed to be different at different points. Suppose, for example, that the track has a radius of 2.87 m and that the driver ...
April 26, 2015

PHYSICS
How do I solve this? Object A is moving due east, while object B is moving due north. They collide and stick together in a completely inelastic collision. Momentum is conserved. Object A has a mass of mA = 16.6 kg and an initial velocity of nu Overscript bar EndScripts ...
April 26, 2015

PHYSICS
A 60.8-kg skateboarder starts out with a speed of 1.84 m/s. He does 90.8 J of work on himself by pushing with his feet against the ground. In addition, friction does -278 J of work on him. In both cases, the forces doing the work are non-conservative. The final speed of the ...
April 22, 2015

A 60.8-kg skateboarder starts out with a speed of 1.84 m/s. He does 90.8 J of work on himself by pushing with his feet against the ground. In addition, friction does -278 J of work on him. In both cases, the forces doing the work are non-conservative. The final speed of the ...
April 22, 2015

A 60.8-kg skateboarder starts out with a speed of 1.84 m/s. He does 90.8 J of work on himself by pushing with his feet against the ground. In addition, friction does -278 J of work on him. In both cases, the forces doing the work are non-conservative. The final speed of the ...
April 22, 2015

PHYSICS
A 60.8-kg skateboarder starts out with a speed of 1.84 m/s. He does 90.8 J of work on himself by pushing with his feet against the ground. In addition, friction does -278 J of work on him. In both cases, the forces doing the work are non-conservative. The final speed of the ...
April 22, 2015

PHYSICS
A 50.5-g golf ball is driven from the tee with an initial speed of 57.4 m/s and rises to a height of 23.2 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. (b) What is its speed when it is 7.97 m below its highest point?
April 22, 2015

PHYSICS
In attempting to pass the puck to a teammate, a hockey player gives it an initial speed of 1.43 m/s. However, this speed is inadequate to compensate for the kinetic friction between the puck and the ice. As a result, the puck travels only one-half the distance between the ...
April 21, 2015

PHYSICS
The drawing shows two frictionless inclines that begin at ground level (h = 0 m) and slope upward at the same angle θ. One track is longer than the other, however. Identical blocks are projected up each track with the same initial speed v0. On the longer track the block ...
April 20, 2015

Physics
A girl is sledding down a slope that is inclined at 30º with respect to the horizontal. The wind is aiding the motion by providing a steady force of 131 N that is parallel to the motion of the sled. The combined mass of the girl and the sled is 59.9 kg, and the ...
April 8, 2015

Physics
The drawing shows a circus clown who weighs 750 N. The coefficient of static friction between the clown’s feet and the ground is 0.630. He pulls vertically downward on a rope that passes around three pulleys and is tied around his feet. What is the minimum pulling force ...
April 8, 2015

Physics
Okay, I solved for a and came out with a=4.28m/s^2 (thank you!). However, when I plugged it into the formula to solve for time, my answer is still incorrect. Am I using the wrong formula?
April 7, 2015

Physics
A girl is sledding down a slope that is inclined at 30º with respect to the horizontal. The wind is aiding the motion by providing a steady force of 131 N that is parallel to the motion of the sled. The combined mass of the girl and the sled is 59.9 kg, and the ...
April 7, 2015

algebra
Marcus plotted the points (0,0),(6,2),(18,6), and (21,7) on a graph. He wrote an equation for the relationship. Find another ordered pair that could be a solution of Marcus's equation.
April 1, 2015

Physics
An eagle is flying horizontally at 5.8 m/s with a fish in its claws. It accidentally drops the fish. (a) How much time passes before the fish's speed doubles? (b) How much additional time would be required for the speed to double again?
March 29, 2015

physics
2 masses m1 and m2 are connected at ends of in-extensible string that passes over pulley find acceleration and tension in pulley.
September 14, 2014

physics (Urgent)!!!!!!!!!!!!!!!!!!!!!!
for part c the correct answer is the first option
January 12, 2014

PHYSICS(help)
q6)a)x_1=sqrt(2*g*R*m/(m*g*alpha+k)) b) t=pi/(2*sqrt((k+alpha*m*g)/m))) c) The block will move back and get catapulted up the circular track
January 10, 2014

chemistry
Hey Dick we are discussing our results here, do tag along. /display.cgi?id=1387456620
December 21, 2013

chemistry
0.000258
December 21, 2013

chemistry
B and both glasses will be weaker
December 21, 2013

chemistry
whoops i am so sorry its B
December 21, 2013

chemistry
i think the former CaCl2 is A, not sure about Nacl
December 21, 2013

chemistry
1.04e-3 p type
December 21, 2013

chemistry
yes 3.88e-7
December 21, 2013

chemistry
BN,AlAs, C,GaAs,GaP
December 21, 2013

chemistry
tetrahedral,2,1,1,no,no
December 21, 2013

chemistry
Dude its wrong again
December 21, 2013

Solid State Chemistry
"Both molecules are ionic but the higher melting point has a larger cohesive energy"
December 20, 2013

Solid State Chemistry
Which molecule ( KI or LiF ) has the higher boiling point? Select the single most important reason below to justify your choice should have the higher melting point Both molecules are nonpolar but the higher melting includes hydrogen bonding Both molecules are nonpolar but the...
December 20, 2013

Chemistry
Sn<Ge<Si
December 20, 2013

chemistry
its alright your intentions were good i can see that so your apology is accepted. sorry for being harsh when all you did was trying to help. i met up with someone who got 94 in the finals and he was kind enouigh to give me some answers 26)1, 3, 0.57; 27 (successively) 27)3,4,4...
December 19, 2013

chemistry
for Nb correct answer is 6.89 Volts. Thanks alot ZM for posting the wrong answer. Next time please double check before sharing your results. I tried the steps anonymous posted for K surface energy from bananas but its giving me the wrong result. Anyone else can give a try?
December 19, 2013

chemistry
Alright i got it 24)0.558 0.000327
December 19, 2013

chemistry
Yeah hi. Hil told us that can someone solve the lead solubility and tell us the end result please? Here are the steps: "This is simple Stoichiometry problem Write down PbI2 -> Pb2+ + 2I- Therefore Ksp = [Pb2+][I-]^2 From the stoich you can derive that Ksp = Cs(2Cs)^2...
December 19, 2013

chemistry
try the stereoisomers one q27, looks pretty straightforward.
December 19, 2013

chemistry
I am also telling the answers of those i myself got wrong in my previous tries. 10 a is 2.42e-6 I got it wrong
December 19, 2013

chemistry
Thanks man, i am telling you all i know.. don't worry, if you get more than 60 overall you will receive your certificate (like i did in bio despite failing in the final, they don't mention your score in the certificate) I don't know anything about gold or the ...
December 19, 2013

chemistry
December 19, 2013

chemistry
thanks for 28 it's correct, as for 12, a is yes and b is 3.88e-7 I got them correct. Thanks again. feel free to brainstorm for other questions.
December 19, 2013

chemistry
You are welcome, thanks. I forgot to convert from KJ/mol to J/mol! If you get anything else, pls do share on this page!
December 19, 2013

chemistry
Okay i am going to list down all the answers i got so far, please assist me in those which i left, if you have any: 1)156.675158119 2)5 3)90.1775147929 4)3s,3p,4s,3d,5s,5p,4f 10,2,14,6 5)-777 2.86e-10 6)8.88 dont know what part b is 7)O2, O2-2 8)tetrahedral,2,1,1,no,no 9)LiF ...
December 19, 2013

chemistry
thanks bob it worked!
December 19, 2013

chemistry
Right... I was thinking the same along the lines of light is "quantized". Thanks!
December 19, 2013

chemistry
even after converting to joules we get the same answer 4.835 which is wrong.
December 19, 2013

physics
vm = 2.213594362 Q = 0.278168471
December 14, 2013

Physics Classical Mechanics
@jessica b) Find Mu_s first Mu_s= (m_p/3 + m_l/2) *cotan (theta)/(m_p+m_l) a) Force = Mu_s*g(m_p+m_l)
December 12, 2013

classical mechanics
v^2/(2*g)
December 10, 2013

Classical Mechanics - Need Help Please
thanks bw your formula worked for both q1 and merry, thanks so much for sharing with us :)
December 8, 2013

Classical Mechanics Physics - Urgent help please
can i have the formula atleast? I just need one more percent to earn the certificate , thank you
December 7, 2013

Classical Mechanics Physics - Urgent help please
greco can you please solve for my rocket question Consider a rocket in space that ejects burned fuel at a speed of vex= 1.5 km/s with respect to the rocket. The rocket burns 9 % of its mass in 310 s (assume the burn rate is constant). (a) What is the speed v of the rocket ...
December 7, 2013

PHYSICS(HELP)
A yoyo of mass m=1 kg and moment of inertia ICM=0.045 kg m2 consists of two solid disks of radius R=0.3 m, connected by a central spindle of radius r=0.225 m and negligible mass. A light string is coiled around the central spindle. The yoyo is placed upright on a flat rough ...
December 6, 2013

Physics
Consider a rocket in space that ejects burned fuel at a speed of vex= 2.0 km/s with respect to the rocket. The rocket burns 8 % of its mass in 300 s (assume the burn rate is constant). (a) What is the speed v of the rocket after a burn time of 150.0 s? (suppose that the rocket...
December 6, 2013

Chemistry
The Young's modulus for a material is 17.0 x 1010 N/m2. The material is stretched to a strain of 2.0 x 10-3. How much elastic energy will be expended? (Express your answer in J/m3) answer is 340000
November 17, 2013

Chemistry
Never mind guys, alphawolfram did it for me :)~ any luck with the last three questions? Today is the deadline!
November 15, 2013

Chemistry
oops I reset it, new value of T is 1091 K somebody help please :'(
November 15, 2013

Chemistry
Thanks Anon and Drew for the formula, I have other exams to prepare for so this was a life saver, I appreciate it truly. I however do not know how to calculate my result using exponents so can someone please solve for T=1373 K? I would be forever grateful. If I find the ...
November 15, 2013

Physics Classical Mechanics
g*(m_1-mu_k*m_2)/(m_1+ m_2+(I_c/R^2)) g*(m_1-mu_k*m_2)/(m_1+ m_2+(I_c/R^2))*t_1^2/2
November 14, 2013

PHYSICS
q7, the answer is a)2*pi*sqrt(((1/3*m+m)*l^2+1/2*m*R^2)/((1/2*m+m)*g*l)) b)2*pi*sqrt(((1/3*m+m)*l^2)/((1/2*m+m)*g*l)) 4a: (m_2*g)/(m_2+I_c/R^2) b: (I_c*m_2*g)/(m_2*R^2+I_c) c: sqrt((2*h*m_2*g*R^2)/(m_2*R^2+I_c))
November 8, 2013

Physics Classical Mechanics
R=2 m, Ic=9000 kg•m², r₀=1.2 m, m=20 kg, F=200 N, Δt=18 s. I=Ic+2I₀=Ic+2m r₀² = =9000+2•20•1.2²=9057.6 kg•m². M=Iα α=M/I=FR/I =200•2/9057.6 = 0.044 rad/s² ω=α•Δt =0.044•...
November 7, 2013

Physics
whoops, bw got here before me. I was wrong there. cheers sasha, hope we can help each other again in times of need.
November 2, 2013

Physics
k can either be 40 or 80.Thanks mouse and to all that helped. We worked as a team and we nailed it :D
November 2, 2013

Physics
@phy: input your derivated function (it should have an x^3 - x in it. In alphawolfram, write series (then your function, then) point (then x_0 value) and the result will be of the form f=f_0 -k(x-x_0), check your value for f_0 and k in that equation (most likely your f_0 is a ...
November 2, 2013

Physics
mouse how did you get q8.b) x2-x1? i know that for part d the answer is The block will stay at its resting position x2. for q6 d1) h~ is always smaller than h and for d2) t~up<t~dn and t~up<tup. both second options. need help with the other parts
November 2, 2013

Physics
Thanks alot mouse! after reading your hints I managed to learn how to use series in wolfram :) There should have been more directions provided with the question, the textbook description was insufficient! I havent got the spring one either but for the airliner question I have ...
November 2, 2013

Physics
a = (v - v0)/t = (1 m/s - 5 m/s)/(1 s) = -4 m/s^2 F = ma N - mg = ma N = m(a+g) N = (w/g)(a+g) N = w(a/g + 1) N = (500 N)(-4 m/s^2 / 10 m/s^2 + 1) = 300 N
November 2, 2013

Physics
240 for ur values
November 2, 2013

physics(help)
for second part it is m*g*tan theta
November 1, 2013

PHYSICS (HELP!!!)
try x_0 = 3.75. i used alphawolfram to plot the graph
November 1, 2013

PHYSICS(HELP)
try PE=0 as its at infinity
November 1, 2013

Finite
One coin is fair and one is weighted so that Pr[H] = [ 1/4]. You randomly select one of the two coins, and flip it 3 times, noting the result of each flip. What is the expected number of heads?
February 23, 2012

world history
I NEED THE SAME ANSWER. For my world history class.
April 5, 2011

math
Given the information: the sampled population is normally distributed, = 10.4, n = 60, and = 81.2. a. Find the 98% confidence interval for b. Interpret the confidence interval in Where do i begin
November 17, 2008

stats
How large a sample should be taken if the population mean is to be estimated with 99% confidence to within \$72? The population has a standard deviation of \$800 Please Help, im stuck
November 17, 2008

MultiMedia
What is the process of making a web portfolio?
August 10, 2008

Accounting
I believe that if a person does not have the answer to the question, he or she should not reply. That is a waste of others time and it is also childish.
July 30, 2008

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