arnab

Any help with this question? At time t = 0, a football player kicks a ball from the point A with position vector (2i + j) m on a horizontal football field. The motion of the ball is modelled as that of a particle moving horizontally with constant velocity (5i + 8j) m s–1. Find (a) the speed of the ball, (b) the position vector of the ball after t seconds. The point B on the field has position vector (10i + 7j) m. © Find the time when the ball is due north of B. At time t = 0, another player starts running due north from B and moves with constant speed v m s–1. Given that he intercepts the ball, d) find the value of v. I worked out part a, b, c but have no idea as to how to do part d :'(

How does heavy metal ion, such as Lead Nitrate, denature an enzyme? I need a detail description of it, up to A2 level standard.Can someone point me to the right direction to this question or give me some hints?

Thank you! i actually realised i made a mistake in my experiment yesterday, so what i said above is not correct. Thanks again for answering my question though.

ahh thanks for clearing that up for me. i was thinking that the hypothesis could be rejected as the majority of the data tell us it is?

Just a quick question, should the Null Hypothesis be accepted or rejected? Null Hypothesis : Same concentrations of substance X & Y will have the same effect on substance Z A experiment was carried out to determine whether the same concentration of X and Y will have the same effect on substance Z. Hence 3different concentration of X & Y was made and mixed with substance Z in a different test tubes. Data was collected for each different concentration of X and Y and its mixing with substance Z. It was found, from the Mann-Whitney U test, that the two weakest concentration of X and Y did not have a significantly different effect on Z but the strongest concentration of X and Y had a significant effect on Z. Now my question is, should the Null hypothesis be rejected based on the fact that the 2weakest concentration doesnt follow the null hypothesis? PS : this is for my A2 unit 6 coursework whose deadline is in 2days time. Any help or advice could be much appreciated! Also just as a side question, can there ever be a situation where a Null hypothesis is neither accepted or rejected?

Thanks for your help i have decided that i am going to use the spearman rank coefficient test for my data + plus calculate the standard deviation and the mean. I hoping from the standard deviation and the mean, i could be able to determine the "95% confidence level test" thing lol. Sorry but my english is not good

Sorry i am panicking a bit at the moment. I had no idea i had to do a statistical test for my coursework and its due in tomorrow! My data does show a linear regression. So as the concentration of the inhibitor increases, the absorbance also increases, hence showing the rate of reaction decreases. Also seen by the fact that the milk went "less clear". I was originally thinking of using the Spearman rank coefficient test, but then i have no idea as to how see my data is within the 5% confidence level :/ What could be your advice, to use the spearman rank test or something else?

so you mean to say, i should be looking to do a MANN-WHITNEY U test?

Hi I recently did a enzyme-inhibition experiment for my unit 6 coursework and i am now on the part where i have to carry out a statistical test on the data i collected from my experiment. This is what my experiment was bascally about : It was just a simple enzyme-inhibition experiment. SO in a simplifed version : 1. I first poured 5cm3 of milk in to 4different test tubes 2. To another set of 4test tube, I then added 2cm3 of trypsin to each of them and then adden 1cm3 of the inhibitor at a concentration 10-4 mol dm^3. 3. I then poured the solution containing the enzyme trypsin and inhibitors into the milk 4. I then took reading for the Absorbance value from the colorimeter, at a regular interval for 15second for the next 4minutes. 5. I then repeated the experiment but with different concentration of the inhibitor, i.e 10^-3 mol dm^3 & 10^-2 mol dm^3 Now i was thinking of using the spearman'r rank correlation Coefficient to determine a relationship between the absorbance value for different inhibitor concentration but i am unsure as to how to go about doing it. Am i right in understanding that i should i just use Absorbance values I collected for the lowest and highest concentration of inhibitor in order to determine there is a relationship between the different concentration of inhibition? Or am i completely wrong in using this statistical test? PLEASE ADVICE!