Jump to content

Hijack from Formula and Collision on Incline help

Brett Nortj

Recommended Posts

On 13/08/2018 at 10:29 PM, Edemardil said:

Hi. So I have a rube goldberg I made in Algodoo and I have to finish a qualitative and quantitative description of it. I am getting an A in this class and I don't know why but there are two parts that I am having trouble with in my machine. If anyone can help.

#1. The first is the collision on the top of the incline. I have to provide the equations and calculate the transfer of energy and momentum from the ball at the bottom of the ramp to the ball at the top. A ball drops into a hole, rolls horizontally for a few meters then rolls up an incline where it interacts with another ball at the top being held there by a lever. The ball going up the ramp pushed the smaller ball through the lever where it drops onto a ramp continuing the system.

How would I calculate the momentum transferred between the ball that rolls up the incline ramp and the ball resting at the top? I know that the momentum is decreasing up the incline as well as the acceleration and velocity. But does the angle of the incline come into play?

So far I've done: 
V'1 = (m1 – m2)/(m1 + m2)(v1) 

V'1 = (42.4kg - 12kg)/(42.4kg + 12kg)(4.30m/s) 

V'1 = 2.40 

V'2 = 2m1 / (m1 + m2) (v1) 

V'2 = 2(42.4kg) / (42.4kg + 12kg) (4.30) 

V'2 = 6.70 

But that's only really the velocity before and after the collision and it's probably wrong because I didn't know how to implement the incline when calculating those either.

For energy transfer, I am going to use:

0.5m1v1and for after the collision 0.5(m1+m2)v22 


#2. This ball then drops down to interact with two vertical "levers" with axles in the middle of them. I'll post photos. I am really having trouble describing them more or less because I don't know what a good description of the objects them selves are. Are they levers? Latches? Hinges? Pendulums? This is keeping me from really describing them quantitatively because I am having trouble finding the right formulas for transferring energy, velocity, force all that, through that part.

Could someone help me or vaguely lead me to a direction to look for both items? 

It is the yellow vertical poles that I am talking about. I have to provide equations about the change in type and amount of energy, and calculate the energy, velocity and force for the system. Which I guess ends with the last lever hitting the ball and the ball falling off the other side onto a "see-saw" but I'm thinking that maybe my system is too big or complicated and I should just do the part where the ball falls from the platform and lands on the see saw. But I will still need to describe the previous system of the small ball interacting with these two yellow levers or whatever.

Link to images: https://imgur.com/a/WZ04zCR

[#1] I think your velocity equation is easy to understand, but, you need only subtract the mass from the velocity, okay?

[#2] For the levers, you need only use a 'tap rotation idea,' okay? Have them spin down like that, looks better too,. Naturally, it will lift up again through pressure applied from the bottom, where a spring can push it back up, and, then repeat process?

Link to comment
Share on other sites


  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.