Recent content by spidey12

This is frustrating me. i know that whatever answer i get for the hands must be divided by two..i get that. But right now i have an equation in which i have four variables and i already know ALL FOUR variables. What am i solving for?

Ok i already had that equation but i dumped it because there is not unknown...we know l1 and l2, we know the weight of the hands and feet (both are 581)..so what am i solving for?

I tried using the center of gravity as the fulcrum but it did not work. I used L1xW/2 for the feet and this did not work. also i tried adding the two lengths together and just getting the midpoint and multiplying that times the Weight but I do not think this is correct.

Homework Statement The drawing shows a person (weight W = 581 N, L1 = 0.829 m, L2 = 0.399 m) doing push-ups. Find the normal force exerted by the floor on each hand and each foot, assuming that the person holds this position. http://img401.imageshack.us/img401/3044/p911zz6.gif...

I am an idiot. I read waaaay to much into this problem. I got it. Thank you.

Homework Statement Kevin has a mass of 89.5 kg and is skating with in-line skates. He sees his 25.50 kg younger brother up ahead standing on the sidewalk, with his back turned. Coming up from behind, he grabs his brother and rolls off at a speed of 2.13 m/s. Ignoring friction, find Kevin's speed...

Aha! I got it. Thank you doc al, you're help is sooooo greatly appreciated.

Ok, how can I find centripedal acceleration if i do not have the velocity? Ac=v2/r

Newtons second law is F=ma. and the second crest is a circle with a radius of 47m. Am i now trying to find the centripedal acceleration? I think I'm way off.

in going from the lowest point on to the top of the crest the skier is losing kinetic energy and gaining potential energy. Also in reference to your Newton's second law hint, how does the energy-work theorem fit into this: Wnc=Ef-E0

Ive been staring at this but i can't seem to squeeze a formula out of it..can you be a little more specifc..

Homework Statement A skier starts from rest at the top of a hill. The skier coasts down the hill and up a second hill, as the drawing illustrates. The crest of the second hill is circular, with a radius of r = 47 m. Neglect friction and air resistance. What must be the height h of the first...

Ok. I solved it. Thanks to the one person who helped me.

I keep getting 160 :( Fc=mv2/r Is that not correct?

Homework Statement A man hanging upside down is holding a partner who weighs 565 N. Assume that the partner moves on a circle that has a radius of 6.50 m. At a swinging speed of 4.40 m/s, what force must the man apply to his partner in the straight-down position? Homework Equations I'm at a...