Nostradumbass

Two masses (mA = 2.5kg) and (mB = 4.0kg) are on inclines and are connected together by a string as shown in the figure . The coefficient of kinetic friction between each mass and its incline is = 0.30.

If mA moves up and mB moves down, determine the acceleration.

Picture: http://img209.imageshack.us/img209/1416/incline1.j...

I just can't figure this out...let me show you what I have so far:

F(mA)= 2.5(g)*sin(51)-2.5(g)cos(51)(.3)= 19-4.6= 14.4N

The downward force of mA is 14.4N

For block B:

F(mB)= 4(g)sin(21)- 4(g)cos(21)(.3)= 14-11= 3N

Block B is falling downward at a force of 4N

So how in the world can the system be moving to the right? Even if it was, there would still be a tension of 14N, divide that be the weight (6.5) and you get 2.1 m/s^2...which is not the right answer.

Also if you have enough time can you help me with this question?...not as big as a deal but would definitely appreciate it.

A 3.0kg block sits on top of a 5.0kg block which is on a horizontal surface. The 5.0-kg block is pulled to the right with a force (F) as shown in the figure . The coefficient of static friction between all surfaces is 0.59 and the kinetic coefficient is 0.39.

a) What is the minimum value of F needed to move the two blocks?

b)If the force is 10% greater than your answer for (a), what is the acceleration of each block?

Picture: http://img191.imageshack.us/img191/753/giancolich0...

Normal Force= 5kg+3kg(9.8)= 78.4

78.4*(.59)=46.3...so the block should require 46.3 N of force to move. Add that to the tension of the 3kg block on top:

3kg*9.8=17.3...the top block should require 17.3N to move +46.3= 63.6N...which is also wrong.

Really need the help guys. 10 points for best explanation or answer.

Well me and a freshman girl have been talking for about a month now, and I was just wondering if this is acceptable to date. Take into consideration that I was actually moved up a grade, so when I turn 18 in August, she will be 16 a couple of weeks later. So its only 2 years age diff. Also, the college I am going to is right down the road from the high school, and I will still be at home for at least 2 more years. I actually have two high school soph friends that are also girls, who date college freshman who go to the same college as I am going.

So my only question is would this be acceptable?