Recent content by Jabababa

Other than the variables, am i on the right track?

Homework Statement An ultra-centrifuge has a cylindrical disk mounted on an axle that is almost frictionless. The disk spins about an axis through its centre as shown. If the disk is spinning with an angular speed of 4.50 x 10^5 rad/s and the driving force is turned off, its spinning slows...

oo so i should use this instead: m(bullet)v + m(Block)v = m(total)v? To find the final velocity? But then on the right hand side i will have 2 unknown variables... edit: should i be doing this: m(bullet)v + m(Block)v = m(total)v 1/2mv^2 = 1/2kx^2 then from 1/2mv^2 = 1/2kx^2 i isolate...

here is an image, sorry i forgot. http://tinypic.com/view.php?pic=143fe55&s=5#.UlfHwlB6bjQ

Homework Statement A 15.0 g bullet with a speed of v = 235 m/s is fired into a block of wood that is initially at rest on a frictionless surface. The block of wood is attached to a horizontal massless spring with a spring constant k = 195 N/m that is initially uncompressed. The other end...

so the static friction is the force that makes the top move with the bottom block. Then is the friction force pointing to the right? Sorry I got the concept but still confuse which direction. Also how do you suggest I tackle on the second question?

I am on this same problem. So let me see if i am on the right track. Since the bottom block is pulled by the string it will move, and in order for the top of the mass to move, the top mass will have to "stick" with the bottom mass. Therefore the force that makes the top mass stay still and move...

alright I just got the velocity and time. Can anyone explain part c to me please. I know how to find the final velocity with the height, initial velocity, the angle and the time, but how do I find the x and y component if I don't know the angle when it just got pass the fence. Thank you.

well no, for part a) i just find the initial velocity...and then use that initial velocity to calculate part b). We have x,initial velocity(from part a) and the angle so its just x = Vocos*t -> t= x/VoCos. Isnt that how you do it for horizontal, since horizontal velocity is constant.

Yes, that's what i mean heh. Not exactly moving them and changing the question. For part b it is easy if i have the initial velocity and the angle, i can just use the horizontal equation ( x= (Vo)(T) to find the time. For part c, I know how to find the final velocity, but how do i find the...

Homework Statement a baseball player hits a home run that just clears a fence that is 19.0 meters high.The fence is located 128 meters from the home player(where the ball is hit). The ball was hit at an angle of 37.0 degrees above the horizontal from a height of 0.900 meters above the ground...

omg thank you! I feel really stupid now :( but it was 2am when i did it, anyways thanks!

Yep, thank you for clarifying. Thats exactly what i did, and the quest ask what is the max height above the water, so the max height above the board added to the 3.00m from the board to the water. Maybe you confused at what i did (or you didnt read), i just used different variables than you...

thank you NascentOxygen Is b) correct as well? The logic behind it seems correct to me. Finding the max height the diver jumps plus the 3.00m below the diving board seems reasonable to me.

Homework Statement A diver jumps off a 3.00 meter high diving board with an initial velocity of 1.75 m/s vertically upward. a) What is the diver's veolcity when she reaches the water? (assume the surface of the water is 3.00 meters below the board.) b) What is the highest point the diver...