How Can a Block Stay on a Moving Cart Without Falling?

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SUMMARY

The discussion revolves around a physics problem involving a 2kg block placed against a moving cart, where the coefficient of static friction is 0.6. The challenge is to determine the frictional force acting on the block when the cart accelerates at 32.27 m/s². Additionally, the discussion includes a problem related to an Atwood's machine, where two masses, m1 and m2, are analyzed based on their kinetic energy and displacement. The user initially calculated the normal force incorrectly, resulting in an erroneous friction force of 130 N, and seeks guidance on deriving a second equation to solve for the masses in the Atwood's machine scenario.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Knowledge of static friction and its calculation
  • Familiarity with kinetic energy equations
  • Basic principles of Atwood's machine mechanics
NEXT STEPS
  • Calculate the correct frictional force using the formula Fs = coefficient * F[SUB]n[/SUB]
  • Explore the relationship between acceleration, speed, and time in the context of Atwood's machine
  • Learn how to derive equations for two-variable systems in physics
  • Investigate the implications of kinetic energy in dynamic systems
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Students studying physics, particularly those focusing on mechanics, as well as educators looking for problem-solving strategies in dynamics and friction.

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Homework Statement



1.Lou bets an innocent stranger that he can place a 2kg block against the side of a cart, and that the block will not fall to the ground, even though Low will use no hooks, ropes, fasteners, magnets, glue, or adhensives of any kind. When the stranger accepts the bet, Lou begins to push the car to the right. The cooefficient of static friction between the block and the cart is 0.6.

Find the force of the friction on the block if a=32.27 m/s2 (It is double the minimum acceleration for the block will not fall to the ground).

2. A simple Atwood's machine uses two masses, m1 and m2. Starting from rest, the speed of the two masses is 4 m/s at the end of 3.0s. At that instant, the kinetic energy of the system is 80 J and each mass has moved a distance of 6m. Determine values of m1 and m2

Homework Equations



Fs= coeff * Fn[/SUB

U=mgy.

The Attempt at a Solution



1.So I found the normal force and time by the coeff of friction. how wever I got 130 N which is the wrong answer. What did I do wrong here ??

2. So I did the U for m1 and m2 and get.

U1=m1g*6
U2=m2g*-6

Then I add 2 equations together and get m1-m2= 80/6g

I know that I need one more equation since I have 2 unknowns but I cannot think of what I can do with the speed and time info. Can anyone help me ?
 
Last edited:
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Does acceleration play any part in number 2 ??
 
Has anyone found out anything yet ?

I was still stuck at figuring out the 2nd equation relating to the given speed and time.
 

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