Recent content by Bones

Homework Statement (a) Calculate the magnitude of the force, FM, required of the "deltoid" muscle to hold up the outstretched arm shown in the figure. The total mass of the arm is 3.3 kg. (b) Calculate the magnitude of the force FJ exerted by the shoulder joint on the upper arm...

I got part a: tnet=mg(24m)-Fmsin15(0.12m)=0 Fmsin15(0.12m)=(3.3kg)(9.8m/s^2)(0.24m) Fm=(3.3kg)(9.8m/s^2)(0.24m)/0.03106m Fm=250N How do I figure out Fj for part b?

Thanks, that helped a lot. I didn't realize the picture did not match up with the problem. No wonder I was not getting the correct numbers.

Does this mean I just leave it out or do I alter the equation in some way?

Homework Statement Three children are trying to balance on a seesaw, which includes a fulcrum rock acting as a pivot at the center (x = 0), and a very light board 5.2 m long (see figure). Two playmates are already on either end. Boy A has a mass of 50 kg, and boy B a mass of 35 kg. Where...

Homework Statement Calculate the magnitude of the force, FM, required of the "deltoid" muscle to hold up the outstretched arm shown in the figure. The total mass of the arm is 3.3 kg. Then, calculate the magnitude of the force FJ exerted by the shoulder joint on the upper arm...

Fa=380N Fbsin(15)=67.29 380N-67.29=fcsinθ 312.71N=Fcsinθ Fbcos(15)=Fccosθ Fbcos(15)= 251.14 so Fccosθ=251.14 we now know Fcsinθ and Fccosθ tanθ=opp/adj θ=arctan(312.71/251.14)= 51.23 degrees so the angle Fa to Fc equals 51.23 degrees+ 90 degrees=141.23 degrees the magnitude...

Homework Statement Three forces are applied to a tree sapling, as shown in the figure, to stabilize it. If vector F A = 380 N and vector F B = 260 N, find vector F C in magnitude and direction. http://www.webassign.net/gianpse4/12-45.gif Homework Equations The Attempt at a...

I think I figured it out. Thanks for your help!

mAgh+0.5mAvA^2=mBgh+0.5mBvB^2 (0.2)(98N)(3.00m)(cos180)=(10kg)(9.8m/s^2)(0)+(0.5)(10kg)(vA)^2=(20kg)(9.8m/s^2)(h)+(0.5)(20kg)(vB)^2 I am not sure about the height of mass B. I don't think this is right either...

Work Force of friction: 0.2*98N*(d)(cos180)=-19.6(d) Change in KE=1/2(20kg)(V)^2-1/2(20kg)(0) -19.6(d)=1/2(20kg)(V)^2 I don't think I am doing this right...

Homework Statement The system of two blocks is released from rest. The pulley is a solid cylinder of mass 5.00kg and radius of 10.0cm. MA is 10.0kg and MB is 20.0kg. The coefficient of kinetic friction between MA and the table is 0.2. Find the velocity of the blocks after moving 3.00m...

Homework Statement A uniform disk turns at 9.5 rev/s around a frictionless spindle. A nonrotating rod, of the same mass as the disk and length equal to the disk's diameter, is dropped onto the freely spinning disk, see the figure. They then turn together around the spindle with their centers...

Thanks!

Homework Statement Consider a planet that rotates one revolution in one day and orbits a star in one year. The planet has mass = 5.6 1024 kg, radius = 6.7 106 m, and is 1.7 1011 km from the star. (a) Determine the angular momentum for the rotating planet about its rotation axis (assume a...