Recent content by crafty2288

Here is the exact problem as my professor wrote it. i didn't post it before, because frankly... His handwriting is impossible to decipher. I am just confused because the mass of the person makes the center of mass EVEN higher. I see no reason why increasing the angle is beneficial.

Homework Statement In using a ladder where the wall is smooth but the floor has a coefficient Us, why is it necessary to make the angle large? Homework Equations The Attempt at a Solution I'm a little confused by this, because I would think that you would want to make the angle...

(Assuming that you are looking at the Plank from the side, and the girl starts at the left. Left being 0m, Right being 6m.) So the center of mass before the move is at 2m... And the center of mass after the move is at 4m...Does this mean that in relation to the surface... The plank has shifted...

Sorry... I'm not sure where to go from here then... The Plank clearly will move, so how then do i calculate it?

Homework Statement A plank of length 6m is lying on a smooth horizontal surface and has a mass of 100kg. A 50kg girl walks from one end of the plank to the other. In this experiment, how far will the plank shift and what direction? Why?Homework Equations v_g will mean girl's velocity relative...

My understanding of the definition of Impulse is that its the average amount of force applied over an amount of time, though. How can you find Impulse without using a change in time?

No, I am not sure... but I don't understand half of what you're doing there. What is this? mgh=1/2mv^2 1/2mv^2 is Kinetic Energy, but why does that equal mgh? How are you finding the velocity after the collision? Can you break that down a little...? Show more steps? I'm really not following...

Homework Statement A 0.5 kg object drops from rest from a 3m high point. On bouncing from Earth it rises to a height of 2m. The collision with Earth lasts for about 10^-4 seconds. i) What is the impulse received by the object? ii)Considering that there is a gravitational force present, Can you...

Oooooooook! g = GM/R^2 So v=sqrt(2gR)... v=sqrt(2(GM/R^2)R)...v=sqrt(2GM/R) Success! Much thanks. This is a study guide for an upcoming physics exam, so I really appreciate you helping me to understand where everything was coming from.

g is 9.8 ms/^2... But I'm not seeing how that makes it equal to v=sqrt(2GM/R)?

I just had to look that up, because I can't find it in the textbook chapter at all. But, I found V=sqrt(GM/r) So KE=(1/2)*m*(sqrtGM/r)^2 or (1/2)*m*(GM/r) So basically that means PE= -GMm/R KE=(1/2) GMm/R I think that's satisfactory for part 1, if I did that right. Because PE is negative, KE...

So just plug in a random mass and a random radius? I don't have any values to use... I'd need a mass, a radius... Which I could pick anything... But what about velocity? I can't just pick something there. And I can't find velocity without a change in distance and time.

Homework Statement i) Show that when a satellite (or planet) is in a circular orbit it's kinetic energy (positive) is one-half of it's potential energy (negative). ii) Show that in order to escape from the Earth you need a speed v=sqrt(2gR) where g=9.8 m/s^2. Neglect Friction and effects of...