Recent content by nando94

I think the slightly different molar mass is due to differences between periodic tables. The answer choices were 2, 6, 5.41 x 10^22, 5.81 x10^22, 1.11 x 10^21. Since your answer was very close to mine, I'm thinking that there was a typo on the quiz. If I saw your answer among the ones above...

I had a multiple choice problem on my pop quiz. How many oxygen atoms are there in .00334 grams of CaS04 X 2H2O. The molar mass is 172 g/mol. So .00334/172 = 1.9 x 10-5 moles x 6 since there are 6 oxygen x 6.022 x 1023 = 7.016 x 1019. None of the answer choices had that. Did I do it wrong...

The I,J,&K were vectors from a previous page that were supposed to be added together to result in <0,0,1>. I got the answer correct. Sorry for the confusion. This textbook is very unclear.

Its part part of my homework for calc 3. I already tried 1,0,0 and it was wrong. The problem gave a hint to do the dot product of the given vector with all the unit vectors. The previous problem was to express the vector <0,0,1> in terms of I,J&,K. The answer to that one was -sqrt(3)/2, 0,1/2...

Express the vector <1,0,0> in terms of I,J,&k. (a)*I + (b)*J + (c)*K You have to find a,b, and c. I know that I,J,&K are unit vectors and so I thought that a = 1, b = 0, c = 0. But the answer has radicals and fractions in it. I don't understand how to arrive at the solution.

1. A car with an initial direction of north moves clockwise one quarter a circle of radius 30 m in 15 s at a constant speed. What is the average velocity? a) 1 m/s north b) 1.41 m/s northeast c) 1.57 m/s southwest d) 2.83 m/s northeast displacement/total time = avg velocity 15pi/15s...

An object is launched from the origin with a velocity of 20 m/s at an angle of 30 degrees above the x axis. The object lands on a roof that is 4 meters high. What is the time when the object hits the roof? a) 1.11 s b) 1.27 s c) 1.33 s d) 1.49 s e) 1.67 s I did 20 (sin(30)) = 10 m/s...

Stuck on these homework problems. 1. A ball is launched 60 degrees above the x-axis to a helicopter that is 110 feet away and 90 feet high. What is the initial velocity required to reach it? I know the equation we have to use is 90 = viT + .5aT^2 and that 90 = vi(cos60)T 2...

I am really stuck on these two homework problems. 1. Basically, there is a cannon which will launch a ball at 60 degrees respect to the x axis. There is also a helicopter 90 feet away from the cannon and 70 feet up. What intial velocity will the cannon ball need to be launched with in order...

my class did a metal activity series lab where we added calcium to 8 different solutions. We have to write the net ionic equations for each reaction but I am stuck getting started on them. Ca(s) + Ca(NO3)2(aq) = ? my guess Ca(s) + Ca(NO3)2(aq) + 2H2O(l) --> Ca(OH)2 + H2(g) + Ca(NO3)(aq) This...

lol cosecant but thanks cause now I am going to ace this test.

Thanks SammyS. I orginally planned to graph 1/cos which was the secant but it made it more confusing lol. Now I see what you mean by graph cos first. My question is that can I also apply to secant and graph sine first or cotangent and graph tangent first? I am going to have all three of...

I have these practice trig problems for a test. I understand the simple graphs but its these more complicated ones. y=2sec(3x-pi) my approach: I first find the period and phase shift. Since the period of a normal secant function which is 2pi. Then the period of this one is 2pi/3. The...

Thanks. I will check it out and see if it answers my question. I would rather take the hard road and understand what I am doing so that I can apply it better. Also are these identities used a lot in calc? I am going to take it next year.

Nah my class is not that far yet. Everything is nearly culminating to calc now.