Homework Help

hey i've got a bit of a tricky (i think it is anyway ) specific heat problem, and i just wanted to check that i'd got it right. so if anyone has a couple of mins free, could they please check my answer? Thanks -Sarah my answer is : [math]c_m = 450 \frac{J}{kg.K} [/math]

I have this question for micro220. It has me stumped A Gram-stain on a bacterial suspension showed that the organism was Gram-positive. The suspension was left overnight and a Gram-stain showed the presence of a mixture of purple and pink staining cells. Explain I’m sure there is a really simple explanation for this, I just can think. Any ideas would be appreciated

can someone tell me why salt make things rusty???

A sports car accelerates from a standing start and covers a quater mile distance (1 mile= 1609) in 6.13 s, calculate the average acceleration of the car in SI unites? is this how you do this prob? find the velocity, then plug it into the average velocity formula to find final velocity, after this, just use the average acceleration formula

That is the graph of the velocity of the rotating object. True or False: A) At time t_3, the magnitude of the tangential acceleration of a point on the rim of the disc is as large as it gets. B) According to convention, the disc rotates counter-clockwise during the interval from t_1 to t_2. C) At time t_3, the radial acceleration of a point on the rim of the disc is zero. D) At time t_2, the angular velocity of the disc is as large as it gets. E) At time t_3, the magnitude of the radial acceleration of a point on the rim of the disc is as large as it gets. F) The acceleration of a point on the rim of the disc points to the axis of the disc at time t_1. I …

For the dissociation reaction of the acid HF: HF(aq) --> H+(aq) + F-(aq) DeltaS is observed to be negative. The BEST explanation for this is: a) This is the expected result since each of the HF molecule produces two ions when it dissociates. b) Hydration of the ions produces the negative value of deltaS. c) The reaction is expected to be exothermic and thus deltaS should be negtaive. d) The reaction is expected to be endothermic and thus deltaS should be negative. e) None of these explain the negative value of deltaS. Can someone please help me with this question? What I know so far is that if deltaS is negative, the reaction must not be spontan…

hey, i am not sure how to approach this problem.... any suggestions on how? Thanks Sarah

So my teacher gave us a due date...October 25 and a summary of what we are to do. Here is what we can do 1) Build a car from SCRATCH that will be only caused to move by the energy provided by dropping a 2kg mass {the mass must stay with the car}. no other source can contribute to the motion of the car. the evaluation will be based on distance traveled compared to your peer's. or 2) Build a tower that is the lightest design but will hold a maximum of 15kg. the tower must be of wood and bonded by glue. you may use pieces of wood no larger than 1/4 inch by 1/4 inch in cross-section. if dowels are used their diameter may be no larger than 1/4 inch. wood may b…

ahhh i don't see where i have gone wrong, i think i've made a small slip somewhere (either that or i am way off track ) anywho, heres what i did (the question is attached as a picture)... Let q = (a,b,c), so c = [math] \frac{a^2 + b^2}{4} [/math] now i get the tangent plane to P at q to be z = [math] \frac{a^2 + b^2}{4} + 0.5a(x - a) + 0.5b(y-b) [/math] and the normal at q to be n = (0.5a)i + (0.5b) -k then i call the vector qF the vector from q to the focus so i get qF to be qF = <-a,-b,1-c> then i figure all i need to do is show that (-k + qF) is parallel to the tangenet plane to P at q. That is that (-k + qF) is perpend…

Ok, so five people have tried to explain this to me but I don't get it. Please help me. A car drives striaght off the edge of a cliff that is 46m high. The police at the scene of the accident note that the point of impact is 138m from the base of the cliff. How fast was the car traveling when it went over the cliff? I need in-depth detail. I cannot get it. thanks. ~onlythorns

Ahh sorry im already stuck on a question. I just need help getting started. Anyways this is the question A tennis player serves a ball horizontally, giving it a speed of 24 m/s from a height of 2.5 m. The player is 12 m from the net. The top of the net is 0.90 m above the court surface. The ball clears the net and lands on the other side. Air resistance is negligible. a)For how long is the ball airborne? b)What is the horizontal displacement? c)What is the velocity at impact? d)By what distance does the ball clear the net. I have no idea how to start this. I dont even know what i have. Can you please help me.

I need help on projectile motion questions because i had to miss a whole lesson for some reason and my teacher said to try some of the questions. Anyways im stuck on this question. A cannon is set at an angle of 45 degrees above the horizontal. A cannon ball leaves the muzzle with a speed of 220 m/s. Air resistance is negligible. Determine the cannonball's a) maximum height b) time of flight c) horizontal range (to the same vertical level) This is what i did. Im not going to do step by step on the part i got. Before these i started i found VIx which is 155.6 m/s and Viy is the same a) At max height Vfy=0( i dont get why but i know thats how you do it) …

have this problem and i am having trouble how to incorporate another function into this problem here is the problem.. #include <iostream> using namespace std; struct node { int data; node *next; }; struct node *push_front ( node *list, int data ) { node *p = new node; p->data = data; p->next = list; list = p; return list; } int main() { node *list = 0; node *save; for ( int i = 0; i < 10; i++ ) list = push_front ( list, rand() % 5 + 1 ); while ( list != 0 ) { save = list->next; cout<< list->data <<' '; delete list; list = save; } cout<<'\n'; } and here is what i am trying to put in.., i have it written but i d…

I am now doing acceleration due to gravity. And i am confused about something. I'll just write down the question. A hot-air balloon is moving with a velocity of 2.1 m/s [uP] when the balloonist drops a ballast (a large mass used for height control) over the edge. The ballast hits the ground 3.8s later. How high was the balloon when the ballast was released? This is what i did. d=Vit + 1/2at^2 d= -2.1(3.8) + 1/2(9.8)(3.8)^2 This is supposed to work but i dont get why we are using 3.8s as the time because at 3.8s the distance/displacement is 0. So how come this works. Can anyone please explain this.

In a multiple regression with statistically significant predictors, the part correlation for any predictor will always be greater or lesser in value than the partial correlation??? Or is it just that it will be higher/lower than the partial correlation if the predictors do not share variance??

[math] m = 0.1g = 0.1 \times 10^{-3} kg [/math] [math] \Delta t = 0.1 s [/math] PE of ball = [math] (0.1 \times 10^{-3} kg)(9.81 ms^{-2})(1m) [/math] but only 0.05% of it is converted into a sound wave so : Energy (E) = [math] (0.0005)(0.1 \times 10^{-3} kg)(9.81 ms^{-2})(1m) [/math] Now Power is Energy per unit time, so Power (P) is: [math] E = \frac{(0.0005)(0.1 \times 10^{-3} kg)(9.81 ms^{-2})(1m)}{0.1s} [/math] Intensity is Power per unit area (since it can be approimated to a point source of sound the area is the surface area of a sphere, [math] 4 \pi r^2 [/math], so Intensity is : [math] I = \frac{(0.0005)(0.1 \times 10^{-3} kg)(9.81 m…

"Three genes (A, B, C) are all on the same chromosome. A is 10 map (cM) units to the left of B, and C is 20 map units to the right of B. A triple heterozygote (ABC/abc) is testcrossed to a tripple recessive (abc/abc). What will be the frequency of each gamete?" This is what I figured so far: ABC abc x abc abc Gametes: ABC (parental) abc (parental) Abc (single recombination) aBC (single recomb) AbC (double recomb) aBc (double recomb) ABc (single recomb) abC (single recomb) If the distance between A and B is 10, and B and C is 20, then if I were to make a theoretical TOTAL …

I really need help on accelerated chemistry (11th grade). The question is: What is the final temperature of water if the initial temperature is 280k and it's heat content is 350.00 kJ and 36,000 Nm of work is performed on it by compression? I have no clue how to do it and any help would be greatly apperciated!

A tennis ball is struck such that it leaves the racket horizontally with a speed of 25.0 m/s. The ball hits the court at a horizontal distance of 19.0 m from the racket. What is the height of the tennis ball when it leaves the racket? I don't want the answer please. I just want to know what formula to use as well as a little tutoring on what the formula means and what the objects in the formula are. Thanks! Klaynos rocks my socks! LOL.

When Cu2SO4·5H2O is heated, the deep blue color of the hydrate changes to a white color as the water evaporates and the hydrate becomes anhydrous. Can anyone please explain to me why this happens? Thank you! Edit: In addition, I notice that there are five molecules of water per formula unit of Copper (II) Sulfate. I know that four of them are attached to the Cu by coordinate covalent bonds, and one is bonded to the sulfate ion. In addition to that last question, how would a water molecule bond to that sulfate ion? Again, please and thank you!

HI! I don't know how to answer this question about stoichiomestry! any ideas? The potassium salt of benzoic acid, potassium benzoate, KC7H5O2, can be made by the action of potassium permanganate on toluene, C7H8. C7H8 + 2 KMnO4 --> 2MnO2 + KOH + H2O If the yield of potassium benzoate cannot be realistically be expected to be more than 71%, what is the minimum number of grams of toluene needed to achieve this yield while producing 11.5 g of potassium benzoate?

Hi, this is my first post and I would really appreciate some help I have for an astronomy homework assignment. The 1st problem involves what would be the net gravitational force exerted on a center asteroid (B) of arbitrary mass 10 placed between two other asteroids, with the left (A) asteroid having an arbirtrary mass of 5 and an arbitrary distance of 3, and the right asteroid © having an arbitrary mass of 10 and an arbitrary distance of 3. I thought that the net gravitational force on (B) would be the gravitational force between (B) and (A) combined with the gravitational force between (B) and ©, but I'm not entirely confident in that idea, and would like assurance …

Im Having diffuculty in working out the nullity of a matrix, the matrix is a=[ 1,-1,1;-1,1,-1;1,-1,1] to find the nullity i was finding the eigenvalues and than working out the nullspace and than working out its dimension, is this correct? the other problem with this is i get to the polynomial equation from det(A-Lambda.I)=0 which ends up being -x^3 + 5x^2 -5x -1 which i dont think is correct, can someone please help. also can someone explain to me what multiplicity is? Cheers

hey heres the question & heres my answer, but i got stuck so yep any help would be greatly apprectiated! ok here is what i have got so far... [math] \epsilon = 1 - \frac{Q_{out}}{Q_{in}} [/math] [math] Q_{out} \ = \ |Q_{d->a}| \ = \ C_v|T_a - T_d| \ = \ C_v(T_d - T_a) [/math] [math] Q_{in} \ = \ Q_{b->c} = C_p(T_c - T_b) [/math] so [math] \epsilon \ = \ 1 - \frac{C_v(T_d - T_a)}{C_p(T_c - T_b)} [/math] but [math] \frac{C_p}{C_y} \ = \ \gamma [/math] So [math] \epsilon = 1 - \frac{T_d - T_a}{ \gamma (T_c - T_b)} [/math] then using PV = nRT [math] \epsilon = 1 + \frac{1}{ \gamma} \frac{P_aV_a - P_d…

This is a very strange question I know, but I really dont know the answer myself- Are there any stomata on the upper epidermis of a leaf? If so, in all plants or just some? I would assume the answer is no, but my honors bio teacher likes to pull tricks