Introductory Physics | Forum profile

Pardon me, but could it be one of those trick questions? The block is "resting" suggests it is not accelerating. Therefore the total force on it is zero. There is quite an explanation of how to find the components of the force of gravity on a ramp here: http://www.physics247.com/physics-ho...help/slope.php

Hi Havok104! Welcome to PF! Hint: call the coefficient of static friction µ. What is the maximum acceleration that the upper block can have without slipping?

Originally Posted by xshezsciencex Conservation of Momentum P(final)y y= 30degrees First, the conservation of momentum says that P(initial)x=P(final)x and P(initial)y=P(final)y. However, there isn't enough information in this question for you to solve it. Are you sure you're not given the initial velocity of the 1180 kg car?

If we decided to take the bottom point of the ladder as our axis of rotation would the friction force produce any torque?

You have seen two methods to solve this problem. Here is a simple third method using center of mass. Consider the ramp as a thin rectangular lamina of mass M. Let co-ordinate of A, B and c are (0,0), ( 12, 9) and (12,0) x-component of the CM ( centroid) of the ramp is ( 0 + 12 + 12)/3 = 8 ft. x-component of the CM of the block is 12. Hence x-component of the CM of the ramp and block system is CMx = (8*M + 12*m)/(M + m) ------(1) When block...

Well, 2 evenings lol, but thanks a lot. When it comes to Physics, I need an extra push. SO to speak... Yeah that's how it is for me too. I had 2 other posts on here from this weekend, and they never got finished. But it's okay I guess. One is better than nothing.

Yes, You don't need to actually work out the resistance, you know power is the ratio of the voltage^2 = 2000*(230^2/250^2) ps. careful about how many significant figures

Hi Cherrybawls, welcome to PF! Originally Posted by Cherrybawls Unfortunately, I have not learned how to solve equations dealing with varying acceleration, so I don't really know what to do... The easiest way to do it is to integrate the a(t) function (acceleration as a function of time) in order to get the final velocity: If you haven't done any calculus, then the above will probably not mean much to you. However, another method,...

thanks holezch, but luckily for me I was able to find a formula on my own in time and the teacher told me that it was right...although i did it this way and am getting the same answer...thanks!

You have the correct expression for the radius of gyration. I know of no other name for it. Your calculation of the moment of inertia looks suspicious, but to be 100% sure, we have to see a picture. I say "suspicious" because the rods are said to be massless so the factor of 1/12 should not be there. Just find the total moment of inertia of the four masses at the corners because that's what the problem appears to want.