# Posts by Chan

Total # Posts: 118

**Related Rates**

(A poignant problem) A 3-foot-tall observer holds a balloon 1 foot in front of her face. Experimentally, the observer releases the balloon and watches as it rises vertically at 5 feet per second. 2 seconds after releasing the the balloon, the observer realizes that the balloon...

*March 2, 2017*

** linear approximation **

Approximate cos (2?/13) by using a linear approximation with f (x) =cos x. cos (2?/13)? f(a) + f ' (a)·h = c, what is h, a, and c? I'm having problems with this one please help

*March 2, 2017*

**Math related rates**

thank you

*March 2, 2017*

**Math related rates **

Water is poured into a conical paper cup at the rate of 3/2 in3/sec (similar to Example 4 in Section 3.7). If the cup is 6 inches tall and the top has a radius of 4 inches, how fast is the water level rising when the water is 2 inches deep? I got (81)/(128*3.14) but it keeps ...

*March 2, 2017*

**Science**

A uniform metal ball (mass m) is tied to the end of a string (massless, length L). The other end of the string is fixed. The ball is moving in a vertical circle centered at the fixed end of the string. Suppose the velocity of the ball at the lowest point is v, what is the ...

*May 3, 2016*

**math**

There were 336 people at a concert. if 2/3 were children, how many chairs were needed for adults?

*February 9, 2016*

**Science**

I need help with questions regarding information about the Galapagos Island volcano. 1. where is the volcano located 2. how long has it been active 3. what kind of volcano is it 4. is it dangerous 5. what is the surrounding area like 6. what else is there to do in the ...

*May 27, 2015*

**Chemistry**

What is the molarity of a solution containing 10.g of NaOH in 700.mL of NaOH solution? Express your answer to two significant figures and include the appropriate units.

*April 7, 2015*

**Chemistry**

Determine the volume, in milliliters, required to prepare each of the following diluted solutions. 40.0mL of a 2.75M KNO3 solution using a 1.00M KNO3 solution 45.0mL of a 2.90M H2SO4 solution using a 6.00M H2SO4 solution 0.700L of a 2.10M NH4Cl solution using a 5.00M NH4Cl ...

*April 7, 2015*

**Chemistry**

Calculate the molarity (M) of the following solutions: 4.00moles of glucose in 3.00L of glucose solution 5.50g of KOH in 4.00L of KOH solution 5.85g of NaCl in 400.mL of NaCl solution

*April 7, 2015*

**science**

Explain why the boiling point of ethyl alcohol (C2H5OH, 78.4 oC) is higher than the boiling point of methyl alcohol (CH3OH, 64.7 oC).

*December 30, 2014*

**science**

Consider the following reaction: CaCO3(s) --> CaO(s) + CO2(g) A mixture of calcium oxide (CaO) and calcium carbonate (CaCO3) had a mass of 15.08 g and was heated to above 840 oC. After heating, 9.83 g of solid was left. What is the mass percentage of CaCO3(s) in the ...

*December 30, 2014*

**CHEM**

Consider the following reaction: 3Pb(NO3)2(aq) +Al2(SO4)3(aq) ¡÷ 3PbSO4(aq) + 2Al(NO3)3(aq) Determine the mass (in gram) of lead(II) sulphate (PbSO4) and aluminium nitrate [Al(NO3)3] formed in the solution when 8.84 g of lead(II) nitrate [Pb(NO3)2] was reacted ...

*December 30, 2014*

**CHEM**

Hydrogen peroxide (H2O2) is decomposed according to the following reaction: 2H2O2 (l) ¡÷ 2H2O (l) + O2 (g) If 6.00 g of aquesous solution containing hydrogen peroxide was decomposed after heating, the mass of oxygen gas collected is 2.40 g, what is the mass ...

*December 30, 2014*

**Math, Fourier Series**

For Fourier Series of f(x)=sin|x| which is an even function, bn should be 0. However, I solved that b1=1 while the rest of the terms =0, meaning bn=0. Is there a mistake?"

*November 20, 2014*

**math**

In how many ways can the letters of the word FACTORING be arranged, without changing the order of the vowels a, o, i

*August 2, 2014*

**math**

Find the number of arrangements of the letters of the word STRENGTH if the order of the consonants must not be changed?

*August 2, 2014*

**English! - Help!**

Wrong, Mew is right. If your questions match this post

*June 3, 2014*

**Physics**

let R1= 16 ohm R2=8ohms for parallel combination of resistances R=R1XR2/(R1+R2) 16*8/(24)=16/3

*May 1, 2014*

**physics**

An AC voltage of the form Δv = (100 V) sin(1000t) is applied to a series RLC circuit. Assume the resistance is 400 , the capacitance is 4.60 µF, and the inductance is 0.500 H. Find the average power delivered to the circuit. W

*December 2, 2013*

**Physics**

I don't get what d0 means. Explain properly

*June 14, 2013*

**Physics**

solution height(h)= 100ft since the object starts at rest, initial speed(U)=0 Final speed (v)= ? since the object is falling under the influence of gravity and downwards a=g= 32.17 ft/s^2 so we have v2=u2+2gh v2= 0+ 2*32.17*100 v2= 6434 v=80.21f/s the final speed was 80.21 f/s

*June 14, 2013*

**Physical Science**

Semiconductor laser lights

*June 12, 2013*

**Chemistry**

CnHn example C6H6(benzene)

*June 12, 2013*

**maths**

5x+6y=37 2x-3y=-4

*May 14, 2013*

**Chemistry**

How many moles of glucose , C6H12O6, can be "burned" biologically when 10.0 mol of oxygen is available. C6H12O6(s) + 602(g)---6CO2(g) + 6H2O(l)

*December 9, 2012*

**chemistry**

Calculate the number of moles of Al2O3 that are produced when 0.6 mol of Fe is produced in the following reaction. 2Al(s) + 3Fe(s)-- 3Fe(s) + Al2O3(s)

*December 9, 2012*

**Chemistry**

How many moles of aluminum are needed to react completely with 1.2 mol of FeO? 2Al(s) + 3FeO(s)-- 3Fe(s) + Al2O3(s)

*December 9, 2012*

**Chemistry**

How many moles of aluminum are needed to react completely with 1.2 mol of FeO? 2Al(s) + 3FeO(s)-- 3Fe(s) + Al2O3(s)

*December 9, 2012*

**STAT**

It is A, I just did the problem for STATS, a paired t-test and CI before and after shipping 95% CI with lower bound for mean difference

*November 15, 2012*

**Math**

I have a drawing with fractions. What does this mean a scale 1:2. I have to draw that picture a scale 1:2. What does that mean?" thank you

*October 21, 2012*

**Linear equation**

Write a linear equation relating x and y x 0 3 6 10 y 2 8 14 22

*October 10, 2012*

**math**

oh thank you very much

*October 2, 2012*

**math**

in isosceles angle ABC, the length of leg AB is 2x+10 and the length of the leg BC is 4x - 18. Find the length of each leg.

*October 2, 2012*

**Geometry**

and how would i draw this

*September 24, 2012*

**Geometry**

Three line segments have the following measure AB=6, BC=3, and AC=8. What conclusions can you draw about points A,B and C?

*September 24, 2012*

**Geometry**

now can you let me know if they are right

*September 12, 2012*

**Geometry**

disconjunctions and conjunctions

*September 12, 2012*

**Geometry**

please tell me if these are correct thank you very much ms sue

*September 12, 2012*

**Geometry**

Let b: Breakfast is a meal Let s: Spring is a season Let h: Halloween is a season s v h = true b ^ s = true ~ s v h = true b ^ ~h = false ~b v ~s = false ~(s ^ h)= false ~(b v ~s) = true ~b ^ ~s = false

*September 12, 2012*

**physics**

An airplane taking off from a landing field has run of 400 m. If it starts from rest and accelerates its motion uniformly and makes the run in 20 seconds. with what velocity did it take off

*July 6, 2012*

**physics**

thanx it really ate my head

*July 3, 2012*

**physics**

A loaded truck is going at a speed of 36 km/hr and a car starts at point 3 km behind the truck with an acceleration of 2 m/s. when will the car overtake the car? What is the distance covered by the car before it overtakes the car?

*July 3, 2012*

**physics**

thanx charlie i got my answer -chan

*July 3, 2012*

**chemistry**

Analyze the properties of a sodium atom and a sodium ion. What are the differences in mass, stability, and reactivity that are caused due to the differences between the sodium atom and sodium ion?

*March 8, 2012*

**COLLEGE**

Trust me, I went through that as well. My family is full of nurse so I was going to be an RN, and for one year I took the class.. then I just said I have to leave this it's not my thing. Now I'm an English major so I applaud you for standing up for yourself too!

*November 1, 2011*

**chemistry**

why 1/t represent k in iodine clock reaction

*October 22, 2011*

**QM**

I have borrowed a sum of $150000 for buying house at 12% simple interest per year at the beginning of a year.The loan has to be repaid by three payment of $10000,$30000 and $X at the end of February, July and November of the same yaer respectively. Find $X.

*October 15, 2011*

**chemistry**

will potassium chloride react with bromine

*July 11, 2011*

**chemistry**

what is the equation of the reaction between potassium sulphite and bromine

*July 11, 2011*

**Physics**

A simple pendulum has a period T on the surface of planet Earth. When taken to the surface of planet X, the same pendulum has a period 2T. a) If the radius of planet X is 1/2 the radius of Earth, what is the mass of Planet X, relative to the mass of Earth? b) Suppose a ...

*May 15, 2011*

**Calculus ll**

Find the radius of convergence and interval of convergence for ‡”(from n=1 to ‡ ) (-1)^n-1 multiplied by n(x-1)^n/(n^2+1)2^n thank you for your help

*April 21, 2011*

**language**

what part of speech is has passed

*November 29, 2010*

**Math**

x(x-3)+4= 3x^2 - 2(x+8) 3

*October 26, 2010*

**math**

(2x^3)-2 3

*October 26, 2010*

**Science**

much force is Mike applying to the 1000 kg car to make it accelerate at a rate of .05 m/s2? I need help understanding this.. I'm really bad at science...>.<

*October 22, 2010*

**Chemistry**

How do I calculate number of moles of K2C2O4 in 20mL of a saturated (300g K2C2O4.H2O per liter) solution....

*September 16, 2010*

**physics**

Hi! could anyone help me to solve this problem please. Three point charges are located at the corners of an equilateral triangle as in the figure below. Find the magnitude and direction of the net electric force on the 1.60 µC charge. (A = 1.60 µC, B = 7.20 µ...

*May 15, 2010*

**physics**

Hi! could anyone help me to solve this problem please. Thank you. Question:An electron has a speed of 0.68 c. (a) Find the speed of a proton that has the same kinetic energy as the electron. (b) Find the speed of a proton that has the same momentum as the electron.

*May 6, 2010*

**physics**

Hi! could anyone please help me with this problem. Thank you so much. Q: The critical angle for total internal reflection for ice surrounded by air is 49.8°. Calculate the Brewster angle for ice if the light is incident from the air.

*April 25, 2010*

**physics**

Please, anyone help me please. Q: An object is placed 17.8 cm from a first converging lens of focal length 13 cm. A second converging lens with focal length 24 cm is placed 10 cm to the right of the first converging lens. (Take the direction to the right to be positive.) (a) ...

*April 19, 2010*

**physics**

Hi! could any help me please, thank you. 1.An object is placed 17.8 cm from a first converging lens of focal length 13 cm. A second converging lens with focal length 24 cm is placed 10 cm to the right of the first converging lens. (Take the direction to the right to be ...

*April 18, 2010*

**Physics**

Hi! Need help please, thank you. Question:In a model AC generator, a 498 turn rectangular coil 14.0 cm by 21 cm rotates at 124 rev/min in a uniform magnetic field of 0.65 T. (a) What is the maximum emf induced in the coil? ___ V (b) What is the instantaneous value of the emf ...

*March 15, 2010*

**physics**

Hi! could anyone help me with this question please, I really don't know how to do this at all. Thank you so much. Question:A 330 turn solenoid with a length of 21.0 cm and a radius of 1.40 cm carries a current of 2.10 A. A second coil of four turns is wrapped tightly ...

*March 15, 2010*

**physics**

Hi! could anyone help me please, I have no idea how to this at all. I try to it but, the did not get the right answer. Thank for your help Oppositely charged parallel plates are separated by 5.34 mm. A potential difference of 600 V exists between the plates. (a) What is the ...

*February 6, 2010*

**physics**

Hi!could anyone help me please, Thank. Gas in a container is at a pressure of 1.3 atm and a volume of 1.0 m3. (a) What is the work done on the gas if it expands at constant pressure to twice its initial volume? (b) What is the work done on the gas if it is compressed at ...

*December 7, 2009*

**physics**

Not much not much

*December 6, 2009*

**physics**

Hey chanley

*December 6, 2009*

**physics**

Hi, could anyone help me please, Thank. Gas in a container is at a pressure of 1.3 atm and a volume of 1.0 m3. (a) What is the work done on the gas if it expands at constant pressure to twice its initial volume? (b) What is the work done on the gas if it is compressed at ...

*December 6, 2009*

**physic**

Hi! Help me please, thank you so much. What mass of water at 28.0 °C must be allowed to come to thermal equilibrium with a 2.05-kg cube of aluminum initially at 1.50 102 °C to lower the temperature of the aluminum to 54.8 °C? Assume any water turned to stream ...

*December 3, 2009*

**physic**

Hi! help me please, Thank you. A spherical steel ball bearing has a diameter of 2.540 cm at 23°C. (a) What is the diameter when its temperature is raised to 94°C? cm (b) What temperature change is required to increase its volume by 0.9%? I only need help on part b.Thank

*December 1, 2009*

**physic**

HI!can anyone help me please, just on part b.Thank you so much. A spherical steel ball bearing has a diameter of 2.540 cm at 23°C. (a) What is the diameter when its temperature is raised to 94°C? ___ cm (b) What temperature change is required to increase its volume by ...

*November 30, 2009*

**physic**

Hi! I really need help on Part B only. (a) Calculate the absolute pressure at the bottom of a freshwater lake at a depth of 28.7 m. Assume the density of the water is 1.00 103 kg/m3 and the air above is at a pressure of 101.3 kPa. (b) What force is exerted by the water on the ...

*November 28, 2009*

**physic**

Hi! need help please thank you so much. Question:(a) Calculate the absolute pressure at the bottom of a freshwater lake at a depth of 28.7 m. Assume the density of the water is 1.00 103 kg/m3 and the air above is at a pressure of 101.3 kPa. ___Pa (b) What force is exerted by ...

*November 26, 2009*

**physic**

hi,need help please.thank. A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 2.00 m and a mass of 525 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 4000 rev/min...

*November 23, 2009*

**physic**

Need Help please. Consider the following mass distribution where the x and y coordinates are given in meters: 5.0 kg at (0.0, 0.0) m, 3.0 kg at (0.0, 4.3) m, and 4.0 kg at (2.8, 0.0) m. Where should a fourth object of 8.2 kg be placed so the center of gravity of the four-...

*November 23, 2009*

**physic**

hi,need help please.thank. A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 2.00 m and a mass of 525 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 4000 rev/min...

*November 22, 2009*

**physics**

hi,need help please.thank. A car is designed to get its energy from a rotating flywheel (solid disk) with a radius of 2.00 m and a mass of 525 kg. Before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 4000 rev/min...

*November 22, 2009*

**physic**

Help me please.Thank you so much A uniform plank of length 2.00 m and mass 25.0 kg is supported by three ropes, as indicated by the blue vectors in the figure below. Find the tension in each rope when a 715 N person is 0.500 m from the left end. T1 have 40.0 degree. magnitude ...

*November 22, 2009*

**physic**

Hi,could anyone help me with this questin please. Thank you so much. some folks on your planet waant to travel to the moon.But what happens to their clocks, it they leave the Earth?for other bodies, like the moon or planets the acceleration due to gravity at their surfaces ...

*November 20, 2009*

**physic**

Hi! could you help this problem please try so many time but, the answer is not correct. Question:The tires on a new compact car have a diameter of 2.0 ft and are warranted for 62,000 miles. (a) Determine the angle (in radians) through which one of these tires will rotate ...

*November 15, 2009*

**physic**

Hi! could you help this problem please try so many time but, the answer is not correct. Question:The tires on a new compact car have a diameter of 2.0 ft and are warranted for 62,000 miles. (a) Determine the angle (in radians) through which one of these tires will rotate ...

*November 15, 2009*

**physic**

Hi!Need help please. Question:A car initially traveling at 24.0 m/s undergoes a constant negative acceleration of magnitude 2.10 m/s2 after its brakes are applied. (a) How many revolutions does each tire make before the car comes to a stop, assuming the car does not skid and ...

*November 14, 2009*

**physic**

Hi!could anyone help me please, I don't get it. Thank you so much for your help. Question:(a) What is the tangential acceleration of a bug on the rim of a 9.0 in. diameter disk if the disk moves from rest to an angular speed of 79 rev/min in 4.0 s? ___m/s2 (b) When the ...

*November 13, 2009*

**physic**

Hi!could anyone help me with this problem please because I been trying so many time and did not get it. Greatly appreciate it. Thank. A 11.2 g bullet is fired horizontally into a 94 g wooden block initially at rest on a horizontal surface. After impact, the block slides 7.5 m ...

*November 2, 2009*

**physic**

Hi! could you help me to start this problem becuase I had try so many time and did not get it right at all please. Thank you so much. A rifle with a weight of 20 N fires a 4.0 g bullet with a speed of 260 m/s. (a) Find the recoil speed of the rifle. (b) If a 775 N man holds ...

*October 29, 2009*

**physic**

please help me.A 5.00 g object moving to the right at +20.0 cm/s makes an elastic head-on collision with a 10.0 g object that is initially at rest. (a) Find the velocity of each object after the collision. 5.00 g object 10.0 g objectt (b) Find the percentage of the initial ...

*October 28, 2009*

**physic**

Hi! I try already but, the answer is wrong could you help me to fix it out. A sledge loaded with bricks has a total mass of 17.8 kg and is pulled at constant speed by a rope inclined at 20.8° above the horizontal. The sledge moves a distance of 20.6 m on a horizontal ...

*October 27, 2009*

**physics**

Two blocks, A and B (with mass 50 kg and 100 kg, respectively), are connected by a string, as shown in the figure below. The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between block A and the incline is µk = 0.24. Determine the ...

*October 26, 2009*

**physic**

please help, I really appriciate you help alot. Question:A 0.34 kg particle has a speed of 2.0 m/s at point A and kinetic energy of 7.5 J at point B. (a) What is its kinetic energy at A? ___ J (b) What is its speed at point B? ____ m/s (c) What is the total work done on the ...

*October 24, 2009*

**physic**

Please help me I have no idea how to do this problem at all. Question:A sledge loaded with bricks has a total mass of 17.8 kg and is pulled at constant speed by a rope inclined at 20.8° above the horizontal. The sledge moves a distance of 20.6 m on a horizontal surface. ...

*October 24, 2009*

**physic**

A block of mass 12.0 kg slides from rest down a frictionless 34.0° incline and is stopped by a strong spring with k = 2.5 104 N/m. The block slides 3.00 m from the point of release to the point where it comes to rest against the spring. When the block comes to rest, how ...

*October 21, 2009*

**physic**

Hooke's law describes a certain light spring of unstretched length 30.0 cm. When one end is attached to the top of a door frame, and a 8.40-kg object is hung from the other end, the length of the spring is 40.00 cm. (a) Find its spring constant. ____ kN/m (b) The load and ...

*October 21, 2009*

**physic**

A 0.34 kg particle has a speed of 2.0 m/s at point A and kinetic energy of 7.5 J at point B. (a) What is its kinetic energy at A? _____ J (b) What is its speed at point B? _____ m/s (c) What is the total work done on the particle as it moves from A to B? _____ J thank you so much

*October 20, 2009*

**physic**

Hi! please help A sledge loaded with bricks has a total mass of 17.8 kg and is pulled at constant speed by a rope inclined at 20.8° above the horizontal. The sledge moves a distance of 20.6 m on a horizontal surface. The coefficient of kinetic friction between the sledge ...

*October 20, 2009*

**physic**

Find the acceleration reached by each of the two objects shown in figure below if the coefficient of kinetic friction between the 7.00 kg object and the plane is 0.270.

*October 16, 2009*

**physic**

The coefficient of static friction between the m = 3.20 kg crate and the 35.0° incline of the figure below is 0.340. What minimum force must be applied to the crate perpendicular to the incline to prevent the crate from sliding down the incline?

*October 16, 2009*

**physic**

An object with mass m1 = 5.00 kg, rests on a frictionless horizontal table and is connected to a cable that passes over a pulley and is then fastened to a hanging object with mass m2 = 10.0 kg, as shown in the figure below. Find the acceleration of each object and the tension ...

*October 16, 2009*

**physic**

Two forces are applied to a car in an effort to move it, as shown in the following figure, where F1 = 439 N and F2 = 365 N. (Assume up and to the right as positive directions.) (a) What is the resultant of these two forces? magnitude___ N direction ____° to the right of ...

*October 15, 2009*