Monday

July 28, 2014

July 28, 2014

Total # Posts: 908

**bio please help Ms sue**

A.) DNA Polymerase B.) Replication C.) Semi conservative

**Science**

I will give you a hint: friction acts against motion.

**Physics**

Horizontal=7.5N*Cos(40) Vertical=7.5N*Sin(40)

**Physics**

F of spring=kx Where: x=0.200m and F=800N Solve for k: k=800/0.200m k=4,000 a.) PE=1/2kx^2 PE=1/2(4,000)(0.200m) PE=400J b.) PE=1/2kx^2 PE=1/2(4,000)(0.0500m) PE=100J ****Check my math.

**biology**

A.) follicle stimulating I am not sure about B, but I believe that it is referring to the LH surge, so I would go with luteinizing hormone or LH.

**Science**

You are correct. Newton's third law.

**biology**

sexual reproduction

**please help**

Auditory.

**Human Biology please help**

I had to use a resource for this one. The first answer I believe is bulb, and the second answer I believe is limbic. Best and good luck.

**Chemistry**

HCl is a strong acid, so yes. The concentration of HCl is equivalent to the concentration of H3O^+ in solution. 10^-14=[H3O^+][OH^-] [H3O^+]= 4.72 X 10^-9 M [OH^-]=10^-14/4.72 X 10^-9 M

**Human Biology please help**

Check your subsequent post.

**Human Biology please help**

I think that the blank is referring to the blood-brain barrier. And the hypothalamus is the correct answer choice for A.

**physics**

Check your previous post.

**physics**

Trish, Its vector addition: ---> ^ I I I Spacing is a problem on this form. But one vector is pointing up (north) and the other is pointing to the right (east). Intuitively, you should be able to see which way the resultant vector will point. However, you may want to go ove...

**physics**

Direction: 45 North East 110^2+100^2=20,000 Magnitude: Sqrt*(20,000)=141N Acceleration: 141N=m*a 141N=100kg*a 141N/100kg=a a=1.41m/s^2

**physics**

45 North East 110^2+100^2=20,000 Sqrt*(20,000)=141N 141N=m*a 141N=100kg*a 141N/100kg=a a=1.41m/s^2

**physics**

t=2pi*sqrt(L/g) t=1.25=2pi*sqrt(L/9.8m/s) Solve for L 9.8m/s^2*(1.25/2pi)^2=L L=0.388m I want to increase the period by 0.200 seconds. How long should I increase the length of the pendulum? The new period will be 1.45 seconds. Use the above equation and solve for L: t=1.45=2pi...

**Physics**

1.) If the box doesn't move, then the Tension in the rope is equal to Fg of the 2.4Kg mass. Fm1=m*a=Fg-T a=0m/s^2 m*0m/s^2=(2.4kg*9.8m/s^2)-T T=Fg=(2.4kg*9.8m/s^2)=23.5N 2.) Fm1=m1*a=T-Fg 2.4kg*a=T-23.52N Fm2=m2*a=Fd-T Fd=mg*Sin45=(6.0kg*9.8m/s^2)*(0.70711) Fd=41.58N Fd>...

**Chemistry**

a) Molarity of the NaOH solution would be lower then expected, causing the molarity of the unknown acid calculated to be lower. b) This would cause you to calculate more volume of the base then actually added. This will cause an increase in the molarity calculated for the unkn...

**Physics**

F=KoQ1Q2/r^2 Where Ko= 8.988 x 10^9 N*m^2/C^2 Q1=+2 µC=2 x 10^-9 C Q2=-2 µC=-2 x 10^-9 C and r=5.0 cm=0.050 m ***Notice that Coulomb's constant contains meters and that it contains coulombs and not microcoulombs. ***Convert centimeters to meters and coulombs an...

**Physics**

I think this is how you tackle this problem: Fnet=T-Fg Where T=550.N Fg=m*g Fnet=m*a m=50.0kg g=9.8m/s^2 and a=? Solve for a: m*a=550.0N-m*g 50.0kg*a=550.0N-(50.0kg*9.8m/s^2) 55.0kg*a=550.0N-490N 55.0kg*a=60N a=60N/55.0kg a=1.091m/s^2 You know acceleration, so solve for time (...

**Chemistry--Typo**

The initial equation should read Ecell=Ecat-Eano cat=cat ano=anode I just want to add one thing: The way that Dr. Bob222 went about balancing the equation is correct, but one thing to keep in mind is that although you must balance the electrons which requires increasing moles ...

**Chemistry**

The reduction potential that is the highest is where reduction is taken place, and reduction takes place at the cathode. Fe2++2e−→Fe;E∘=−0.440 V <==Cathode Al3++3e−→Al;E∘=−1.66 V <==Anode Ecell=Ecat-Ered Ecell=−0.440 ...

**Science**

Yes.

**Science**

B=allele for black color b=allele for the recessive color When you perform a cross between the two guinea pigs, there is a 75% chance that EACH offspring will express black as the phenotype, and there is 25% chance that EACH guinea pig will express the recessive phenotype. Out...

**Chemistry**

Anode oxidation Mg -----> Mg2^+ + 2e^- Cathode reduction Ni2^+ 2 e^- -------> Ni

**chemisty**

pH=-log[H^+] 10^-(pH)=[H^+] Answer contains ONLY 1 significant figure.

**Physics (acceleration)-Typo Correction **

Typo correction. Look for ^&***" for correction . 1. a.) Vf=Vi +at Where Vf=? Vi=0m/s a=0.5m/s^s t=12s Solve for Vf: Vf=0m/s +(0.5m/s^2)*(12s) Vf=6m/s b.) d=Vi*t + 1/2at^2 Where d=? Vi=0m/s a=0.5m/s^s t=10s Solve for d: d=0m/s*(12s) + 1/2(0.5m/s^2)(10s)^2 d=0 +25m d=25m c...

**Physics (acceleration)**

1. a.) Vf=Vi +at Where Vf=? Vi=0m/s a=0.5m/s^s t=12s Solve for Vf: Vf=0m/s +(0.5m/s^2)*(12s) Vf=6m/s b.) d=Vi*t + 1/2at^2 Where d=? Vi=0m/s a=0.5m/s^s t=10s Solve for d: d=0m/s*(12s) + 1/2(0.5m/s^2)(10s)^2 d=0 +25m d=25m c.) d=Vi*t + 1/2at^2 Where d=? Vi=0m/s a=0.5m/s^s t=40s ...

**Algebra II**

Two equations: 1.) Amadeus 760miles=R1*T1 2.) Salieri 220miles=R2*T2 Let R1=R2+40 and Let T1=2*T2 Substitute into equations and solve: 760miles=(R2+40)*(2*T2) Solving for T2: 380 miles/(R2+40)=T2 Plug into equation 2 and solve for R2: 220 miles=R2*[380 miles/(R2+40)] 220 miles...

**Chemistry-Typo Fix**

**Fixed a typo that probably would cause confusion. Use the gas law and solve for the pressure: PV=nRT Where n=moles of gas L=volume R=62.3637 L·Torr/mol·K and T=273.15K + 25 C=298.15K The density of the gas is 8.0g/L and the molecular weight of the gas is 75 g/m...

**Chemistry**

Use the gas law and solve for the pressure: PV=nRT Where n=moles of gas L=volume R=62.3637 L·Torr/mol·K and T=273.15K + 25 C=298.15K The density of the gas is 8.0g/L and the molecular weight of the gas is 75 g/mol 8.0g//75g/mol= x mol/L Rearrangement of the gas l...

**Physical Science**

q=m*c*change in temperature Where m=mass c=specific heat change in temperature=final temp-initial temp=29C-7C=22 C You can figure it out from here.

**Science**

3. exerts an equal and opposite force on the hammer.

**chemistry**

125g of MgSO4 • 7 H2O*(1 mole/ 246.47g)= moles of MgSO4 • 7 H2O Moles of MgSO4•7H2O*(7 moles of H2O/1 mole of MgSO4•7H2O)= moles of H2O Moles of H2O*(18.00g/mole)= mass of H2O in grams

**science**

You need a total volume of 674mL=0.674L Solve for moles of ethanol: Moles=Molarity*Volume (L) Moles=0.854 M*0.674L Moles of ethanol*(46.07g/mole)= mass of ethanol Density=Mass/Volume So, Mass/Density=Volume (mL) Mass of ethanol/0.789 g/mL=Volume (mL)

**moles**

I THINK that the reaction is a 1 to 1 mole reaction , so you should need 3.5 moles of H2O. 3.5 moles of H2O*(18.00g/1 mole)= mass of H2O ***2-significant figures. Like I said, I think 3.5 moles of H2O is needed.

**chemistry**

You are too nice. At least you can understand my typos. When I help others on another forum, I can edit my answers, so I do not look like an idiot, but on this forum I can not.

**chemistry**

1,000meters=1km So, you have to make this relationship a fraction. 1,000m/1km. But how do I organize it in a way that meters goes away and kilometers remain? (1km/1000m) So if I multiply the ration this way, by my intermediate answer that is in meters, then the meters cross ca...

**chemistry**

No. 1.07 x 10^16 is in meters; you have to take the whole thing and divide it by 1,000, not just 1.07. So, 1.07 x 10^16 m*(1km/1,000m)= your answer in Km ****Notice how the m's cancel and you are only left with km. The FINAL ANSWER SHOUD BE 1.07 x 10^13

**chemistry**

No, 1.06812e+16 is correct. But you are only suppose to report three significant figures: 1.07 e+16

**chemistry**

Yes, but only three significant figures. So, a number, decimal followed by two more numbers.

**chemistry**

You will get an answer that is very large, so you will have to use scientific notation. Report no more then 3 significant figures.

**chemistry-aira**

Yes, 35,604,000 seconds, but what do you do with it once you have found the time that it takes in seconds?

**chemistry**

1 year=365 days 365 + 47=412 days total 412 days*(24hours/1 day)= 9,888 hours 9,888 hours + 2 hours=9,890 hours total 9,890 hours total*(60 min/1 hour)*(60 sec/1 min)= total time in seconds 3.00 x 10^8 m/s*total time in seconds= distance in meters distance in meters*(1 kilomet...

**Physics-Correction!!!**

The force supplied by kinetic friction will do work on the box, and stop the box from eventually moving any further up the ramp. Initially, the box has kinetic energy, but will eventually be stopped by the force of friction. Work=F*d=µk*m*g*(Sin(theta)+Cos(theta)*d 1/2mv...

**Physics-Additional Detail**

ï¿½k=coefficient of kinetic friction

**Physics**

The force supplied by kinetic friction will do work on the box, and stop the box from eventually moving any further up the ramp. Initially, the box has kinetic energy, but will eventually be stopped by the force of friction. Work=F*d=µk*m*g*Sin(theta)*d 1/2mv^2=Kinetic E...

**Physics**

ï¿½k=coefficient of static friction

**Physics**

Ignore my initial post, I forgot to include one of the components for the frictional force. Fk=F Fk=200N Fk=µk*mg*Cos(theta)+ µk*mg*Cos(theta) 200N=µk*(150kg)*(9.8m/s^2)*[Cos(35)+ Sin(35)] 200N=µk*159.8N*[0.819 + 0.574] 200N=µk*159.8N*[1.393] 200...

**Physics-additional detail**

Âµk=coefficient of static friction

**Physics**

Fk=F Fk=200N Fk=Âµk*mg*Cos(theta) 200N=Âµk*(150kg)*(9.8m/s^2)*Cos(35) 200N=Âµk*1470N*0.819 200N=Âµk*1204N 200N/1204N=Âµk Âµk=0.166

**Physics--Correction **

he force supplied by kinetic friction will do work on the box, and stop the box from eventually moving any further up the ramp. Initially, the box has kinetic energy, but will eventually be stopped by the force of friction. Work=F*d=Âµk*m*g*(Sin(theta)+Cos(theta)*d...

**Physics**

The force supplied by kinetic friction will do work on the box, and stop the box from eventually moving any further up the ramp. Initially, the box has kinetic energy, but will eventually be stopped by the force of friction. Work=F*d=µk*m*g*Sin(theta)*d 1/2mv^2=Kinetic E...

**Math-Typo**

Fixed a typo: Look for #%^ I think you can do the following: P*R=I Where P=principal=amount invested (#$^) R=interest rate and I=amount in interest You have two equations. 1.) P*R=400 and (P+400)*R=432 ****The principal now includes the interest from the previous year. Solving...

**Math**

I think you can do the following: P*R=I Where P=principal=amount investere R=interest rate and I=amount in interest You have two equations. 1.) P*R=400 and (P+400)*R=432 ****The principal now includes the interest from the previous year. Solving for P (Equation 1): P=400/R Plu...

**math**

10 numbers, total and 23 is only 1 number. So, 9/10 numbers will be numbers besides 23. or 90% chance

**Math**

The equation for the line in Y-intercept form is y=mx+b Where m=slope and b=y-intercept Which answer choice has m=-3? Off the bat, you should eliminate two answer choices (B and C) because m is positive and not negative. This leaves you with two answer choices, which you can u...

**Chemistry-Additional Steps**

Answer should contain 3-significant figures.

**Chemistry**

1 mole=119.00g Solve for moles: 25.5g*(1 mole/119.00g)= moles of KBr Molarity of KBr= moles of KBr/1.75L

**Alegbra**

Take the natural log (Ln) of each side of the equation to isolate the variable. Ln(6^x)=Ln(1/36) x*Ln(6)=Ln(1/36) Solve for x: x=Ln(1/36)/Ln(6) The other problem is exactly the same.

**Science: Please check answer**

Bingo!! Best and good luck.

**Science: Please check answer**

You could have just had a typo, but I just want to make sure that you understand.

**Science: Please check answer**

Yes and no, since the rocket is decelerating. So, is the final answer 280,000 km/hr^2 or is it - 280,000 km/hr^2?

**Science: Please check answer**

Report your answer as --- km/hr^2.

**Science: Please check answer**

You have a mistake: the rate is given in units of km/hr, but the time is given in seconds. You have to convert 90seconds to hours before proceeding with the calculations. 90 seconds*(1 min/60 seconds)*(1 hr/60 minutes)= time in hours. (17,000km/hr-24,000km/hr)/time in hours=co...

**chemistry**

Convert 10.2mm to cm: 10.2mm*(10^-1cm/1mm)=10.2 x 10^-1 cm Find the volume of the cube: (10.5cm)*(5.25cm)*(10.2 x 10^-1 cm)=volume of cube Density=mass/volume Solve for mass: Density*Volume=mass 7.86g/cm^3*Volume of cube=mass

**Physics**

You are missing some information, like an angle.

**chemistry-Additional Steps**

The answer that is given to you will be in years. Take To and do the following with it: To*(365 days/1 year)*(24hrs/1 day)*(60mins/1 Hr)= answer in minutes. Remember, no more than four significant figures.

**chemistry**

Use the following formula: T1/2 = T*ln(2)/ln(Ao/At) Where T1/2=0.03920 years T=? Ao=100% and At=53.25% Solve for T: (T1/2)/[[ln(2)/ln(Ao/At)]= To To=(0.03920)/[ln(2)/ln(100/53.25)] Answer contains four significant figures.

**Physics**

Ignore the work done. This is a multistep problem and Fnet doesn't equal 220N. Fnet=Fthrust-Fk Fnet=220N-74.48N=145.52N Solve for acceleration: F=ma a=F/m a=145.52N/76kg a=1.91m/s^2 Use the following kinematic equation: d=vi*t+1/2at^2 where Vi=0m/s a=1.91m/s^2 t=15s and d=...

**Physics**

After the skis run out of fuel, the Force of kinetic friction will do work on the skier. 220N=Fµk*d Solve for d: 220N=m*g*µk*d 220N=(76kg)*(9.8m/s^2)*(0.1)*d 220N=74.48N*d d=220N/74.48N d=2.95m=3m I could be wrong.

**Physics**

The cabinet is being pulled with 200N and is being rested by a force equal to 200N. That is why it is not being moved. Although the force of static friction can equal Fk=µs*F=m*g*µs=(30kg)*(9.8m/s^2)*(0.80)=235 N. It is not resisting the 200N force with 235N. Imagi...

**Chemistry 104**

Ka of HSO3^-=6.3 x 10^-8 HSO3^- --------> H^+ + SO3^- Ka=[H^+][SO3^-]/[HSO3^-] E of the ICE chart is the following: [H^+]..[SO3^-]...[HSO3^-] x............x............0.3M-x Plug in values to Ka equation: Ka=[x][x]/[0.3M-x] I am going to assume x is small and ignore, but w...

**Chemistry 104**

Ka of HSO3^-=6.3 x 10^-8 HSO3^- --------> H^+ + SO3^- Ka=[H^+][SO3^-]/[HSO3^-] E of the ICE chart is the following: [H^+]..[SO3^-]...[HSO3^-] x............x............0.3M-x Plug in values to Ka equation: Ka=[x][x]/[0.3M-x] I am going to assume x is small and ignore, but w...

**chemistry**

a. 45.3L x 10 mol/L = 1 sig fig b. 67.894 g ÷ 2.56 L = 3 sig figs c. 45.3m + 12.344m + 1000m – 1.34m = answer to the least amount of uncertainty d. 35cm + 8.3m + 75.341 km + 80,000 mm = answer to the least amount of uncertainty e. (43.7m + 39.3cm) ÷ 25.332 m...

**chemistry**

a. 45.3L x 10 mol/L = 1 sig fig b. 67.894 g ÷ 2.56 L = 3 sig figs c. 45.3m + 12.344m + 1000m – 1.34m = answer to the lease amount of uncertainty d. 35cm + 8.3m + 75.341 km + 80,000 mm = answer to the lease amount of uncertainty e. (43.7m + 39.3cm) ÷ 25.332 m...

**chemistry**

Excuse the other posts. a. 1.2056 x 10^4 m: ==> 5 b. 1 x 10^89 km: ==> 1 c. 12,000 L: ==>2 Trailing 0's are not significant if no decimal is present. d. 0.000345 cm: ==>3 Leading 0's are not significant. e. 1.00036 mL: ==>6 f. 0.2056000 m: ==> 7 Trail...

**chemistry**

a. 1.2056 x 10^4 m: ==> 5 b. 1 x 10^89 km: ==> 1 c. 12,000 L: ==>2 Trailing 0's are significant if no decimal is present. d. 0.000345 cm: ==>3 Leading 0's are significant. e. 1.00036 mL: f. 0.2056000 m: ==> 7

**chemistry**

a. 1.2056 x 10^4 m: ==> 5 b. 1 x 10^89 km: ==> 1 c. 12,000 L: ==>2 Trailing 0's are significant if no decimal is present. d. 0.000345 cm: ==>3 Leading 0's are significant. e. 1.00036 mL: f. 0.2056000 m: ==> 7

**Physics HELP!!!!!!!!-**

** Fixed a typo: look for ** You can use the fact that 1 mole of a gas occupy's a volume of 22.4L at STP, which gives you the initial volume faster then using the gas law, but both ways will return the same initial volume. I suspect that you made an error in your calculati...

**Physics HELP!!!!!!!!**

You can use the fact that 1 mole of a gas occupy's a volume of 22.4L at STP, which gives you the initial volume faster then using the gas law, but both ways will return the same initial volume. I suspect that you made an error in your calculations, and the work value for t...

**Physics HELP!!!!!!!!**

Use the gas law and solve for the volume. PV=nRT Where P=1.00 atm V=? R=0.0821 liter·atm/mol·K T=273.15K and n=0.021 *** Typo correction V=nRT/P Answer should contain 2-significant figures, but keep 3 for intermediate calculations. V*0.411=Final Volume Final Volu...

**Physics HELP!!!!!!!!**

Use the gas law and solve for the volume. PV=nRT Where P=1.00 atm V=? R=0.0821 liter·atm/mol·K T=273.15K and n=0.021 V=nRT Answer should contain 2-significant figures, but keep 3 for intermediate calculations. V*0.411=Final Volume Final Volume-Volume calculated f...

**(2-8) Chemistry - Science (Dr. Bob222)**

Okay, Dr. Bob222 is discussing isothermal processes, which he quoted from Wikipedia and is true. However, this also causes no change in internal energy, because no change in heat takes place. So, you rarely see one of theses calculations. But it is true. ======================...

**(2-8) Chemistry - Science (Dr. Bob222)**

Also, could you tell me please what processes would result in work=0 (beside the constant volume)? I could be wrong, but I think constant volume is the only process resulting in W=0.

**(2-8) Chemistry - Science (Dr. Bob222)**

I would just look at it like this: Work done by the system: Work=- and q= N/A Work done onto the system: Work=+ and q=N/A Heat released from the system: Work=N/A and q=- Evaluate each answer choice with the chart. A) The internal energy of a system increases when more work is ...

**physics**

You have to tackle these type of problem in steps: Solve for the first leg of the trip, and then solve for the second leg of the trip. Use the following equation for the first leg of the trip: Vf^2=Vi^2+2ad Where d=900m*(1/4)=225m a=2.2 m/s^2 Vi=0m/s and Vf=? Solve for Vf: Vf^...

**Sciene**

See ** for correction; I made a blunder, which could cause confusion. The answer would be no. Mitosis produces two identical daughter cells from one parent cell. Whereas meiosis is the process of producing four daughter cells from one parent cell, with each cell being differen...

**Sciene**

The answer would be no. Mitosis produces two identical daughter cells from one parent cell. Whereas meiosis is the process of producing four daughter cells from one parent cell, with each cell being different from the original parent cell, and each daughter cell having half of...

**physics**

I saw this earlier and I tried using kinematic equations, but I could't reason 80m as the answer. When you plug in a value for a that is less then or greater then 0, you do not calculate 80m, at least I didn't. So, I am not sure what MathMate did, and I do not think th...

**Chemistry 104**

Made a mistake that Dr. Bob222 caught in an earlier post. See your earlier post for corrections. Current=charge/time (s) Where current=3.40A Convert hr to seconds (s): 1.80hrs*(60 min/1 hr)*(1 min/60s)= time in s Solve for charge: seconds*current=charge (C) 1 mole of e^-s=9.65...

**Chemistry**

Whats the equation to form NH2? N2 +3H2 -----> 2NH3 So, you need 3 moles of H2 gas for 1 mole of N2: How many moles of hydrogen are present in 2.79 g of Hydrogen? 2.79 g of H2*(1 mole/2.016g)=1.384 moles of H2 1.384 moles of H2 requires how many moles of N2? 1.384 moles of ...

**Chemistry 104 --Opps**

Dr. Bob222 caught that for me. Look for **** for corrections. Current=charge/time (s) Where current=3.40A Convert hr to seconds (s): 1.80hrs*(60 min/1 hr)*(1 min/60s)= time in s Solve for charge: seconds*current=charge (C) 1 mole of e^-s=9.65 x 10^4 C Solve for moles: **** C*(...

**Chemistry 104**

Current=charge/time (s) Where current=3.40A Convert hr to seconds (s): 1.80hrs*(60 min/1 hr)*(1 min/60s)= time in s Solve for charge: seconds*current=charge (C) 1 mole of e^-s=9.65 x 10 4 C Solve for moles: C*(1 mole/9.65 x 10 4 C)=moles of Ni(NO3)2 Solve for mass: moles of Ni...

**chemistry**

1 mole of KOH=56.11g and 250mL=0.250L Solve for moles: 5.00g*(1 mole/56.11g)= moles of KOH Molarity=moles/volume (L)

**(12)Chemistry - Science (Dr. Bob222)**

I initially did it without assuming that volume wasn't constant and I calculated what Dr. Bob222 calculated, but I assumed that it was about 15J, so I just assumed that it was incorrect without checking a source to see if I needed to use a conversion. That is why I said I ...

**(12)Chemistry - Science (Dr. Bob222)**

I believe, and I can be wrong, that you have to assume that VOLUME and Pressure remains constant. E=work pressure*change volume+heat Work (W)=pressure*change in volume and Heat (q)=ncdT If there is no change in volume, then work=0 and the equation becomes the following: E=q=nc...

**(23.Chemistry - Science (Dr. Bob222)**

I'm not Dr. Bob222, but I play on this site every now in then. I think you are confused because of the wording of the question; you are not calculating Eo based on the information that a chart in your book gives you, but they are just giving you Eo and asking you based on ...

**Chemistry**

Molarity of HNO3=moles/volume (L) 1 mole of HNO3=63.01 g and 875mL=0.875L Solve for moles: 22.3g*(1 mole/63.01g)=moles of HNO3 Molarity of HNO3=moles of HNO3/0.875L ***Answer contains no more then 3-significant figures.

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