Effects of Rolling Resistance on Tension and Acceleration in an Atwood Machine

AI Thread Summary
The discussion focuses on an Atwood Machine experiment involving rolling resistance, where block A is on a surface and block B is hanging. Questions addressed the relationship between tension in the string and gravitational force, as well as the acceleration of the hanging mass compared to standard gravitational acceleration. Calculations indicated that both tension and acceleration were less than expected due to the presence of rolling resistance. A third question explored how these values would change if rolling resistance were eliminated, leading to slightly smaller but insignificant results. The need for visual aids like sketches or Free Body Diagrams was emphasized for better understanding.
a78
Messages
3
Reaction score
0
We had a lab using an Atwood Machine with block A being on the surface and block B as the hanging object with different masses each round. Rolling resistance was present. Question 1 asked whether or not the tension in the string was less than, greater than or equal to the magnitude of the gravitation force acting on the hanging mass (as the objects are accelerating). Question 2 asked, while the carts were accelerating, was the acceleration of the hanging mass less than, greater than or equal to the standard gravitational acceleration. After applying Newtons law, I calculated that for both q1 and q2 the values were less than.

Q3 asks how would your answers to the first two questions change if the rolling resistance of the cart could be reduced to zero? Explain why this must be. I calculated this by doing Fnet(y)=-ma(y) and my answers were slightly smaller but insignificant. I am not sure why this is.
 
Physics news on Phys.org
a78 said:
We had a lab using an Atwood Machine with block A being on the surface and block B as the hanging object with different masses each round. Rolling resistance was present. Question 1 asked whether or not the tension in the string was less than, greater than or equal to the magnitude of the gravitation force acting on the hanging mass (as the objects are accelerating). Question 2 asked, while the carts were accelerating, was the acceleration of the hanging mass less than, greater than or equal to the standard gravitational acceleration. After applying Newtons law, I calculated that for both q1 and q2 the values were less than.

Q3 asks how would your answers to the first two questions change if the rolling resistance of the cart could be reduced to zero? Explain why this must be. I calculated this by doing Fnet(y)=-ma(y) and my answers were slightly smaller but insignificant. I am not sure why this is.
Welcome to the PF.

First, please use the Homework Help Template that you are provided when starting a new schoolwork thread here. I'll paste in a copy below.

Also, it's very hard to visualize the setups you are asking about. Can you post sketches or pictures of the situations? Also, can you draw Free Body Diagrams (FBDs) for all of the pieces involved? Thanks.

Homework Statement

Homework Equations

The Attempt at a Solution

 
There was a track on the table and a cart was placed on it. There was a pulley attached to the cart and hanging at the edge of the table was a "hanging mass". On block A there was rolling resistance/friction between the block and the table as well as Fg and tension from the pulley/string. On block B there was Fg as well as tension from the rope. (This is my first time posting so I'm not sure how to ad in a drawing).
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top