A log weighs 800N and has its center of gravity at the midpoint. Find the lowest coefficient of static friction necessary to keep the log from slipping.
Answer (1.01)
http://img115.imageshack.us/img115/8407/physicsproblem3ox.th.png
Ok, so, i started out by finding my torque and force...
Oh, so the density of the rod is not constant. That part makes sense, but why was an equation for the mass given? The other thread explains that combining the equations gives the result, but it just isn't making sense yet. Thanks so much for your help,
Dan
I found this thread on the internet, but I guess it still doesn't clear things up.
"Okay, I'll do the first one for you.
The line density is given as \lambda=\lambda_{0}x
It's no wonder that you are stuck with this exercise, because this expression is by itself meaningless.
The correct...
Find the moment of inertia of a rod about an axis through its center if the mass per unit length is lambda = lambda (sub zero) time X.
Answer (I = (1/8) M L^2)
This problem is totally throwing me off. Normally lambda is equal to (M/L) so I am not sure what this new formula is doing to the...
I guess I'm still a little confused. If the car went from 0 to 60 in 10 seconds, then the acceleration must be 6 feet/sec^2. So if the mass of the car is 3000/32 or 93.75 the force acting on the car is m X a = 562.5 lbs. This is where I get stuck. Thanks again for the quick response!
Dan
I just need a little help going about solving this problem. This is first problem in this lesson, and it is driving me crazy. Any help would be great!
A 3000 lb car is accelerated from 0 to 60mph in 10 seconds. Find the torque needed if the car has wheels of 1 ft. Ans (825 ft lbs)
We know...
That was totally the right approach for the problem. I found the PE at the top of the swing, and then converted that PE to KE at the point of the collision. After calculating the collision velocities, I reconverted back into energy and found the height at which it would swing. Thanks for all the...
Oh, I see what you guys are saying. So the ball on the end rotates down and slams against the other ball. I was sitting there trying to figure out where collisions came into play and it originally wasn’t making sense. Ill do some work on the problem and update the post. Thanks so much!
Dan
I was assigned this problem from my physics teacher, but it doesn't really make sense. I would ask the teacher, but I don't go back to class for a few days. At this point, I just need help trying to understand what the problem is asking for. Thanks very much in advance for any help.
Find the...
Thank you so much for helping me through this one. I was actually using 3 as the radius, (instead of 3 for the main rod + 1 for the car = 4). I was confused about the setup of the problem. Once the centripetal force was correct, the rest of the problem went great. Thanks again for everything!
Dan
Yeah,
The naming convention is totaly my fault. I did mean rotations per minute by the rpms. And I did mean to put radians/second by puting rads.
Ive been thinking about it, and I guess I'm confused how radial force works. My book explains that radial force is the amount of force needed to...
Another quick question. If the main rod is spinning at 6rpms, that means that it is spinning at (2* Pi)/(60) rads or .628319. Converting the .628319 rads to translational velocity gives 1.88496m per second This means that if the car is rotating around the rod at 3m per sec, at the top of the...