Ball Bearing Speed Calculation in Elevator

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SUMMARY

The discussion revolves around calculating the speed of a ball bearing that rolls off the floor of an elevator moving upward at 0.52 m/s with an acceleration of 2.4 m/s². After the ball bearing rolls off, it experiences free fall with an acceleration of 9.81 m/s² due to gravity, while initially maintaining the elevator's upward velocity. The confusion regarding the acceleration stems from the transition from the elevator's motion to free fall, clarifying that the ball bearing's acceleration changes once it leaves the elevator.

PREREQUISITES
  • Understanding of kinematic equations, specifically v = u + at
  • Knowledge of gravitational acceleration (9.81 m/s²)
  • Familiarity with concepts of relative motion in physics
  • Basic principles of free fall and projectile motion
NEXT STEPS
  • Study kinematic equations in-depth, focusing on their application in varying contexts
  • Learn about the effects of gravity on objects in free fall
  • Explore relative motion and how it applies to objects in moving frames of reference
  • Investigate the principles of projectile motion and its calculations
USEFUL FOR

Physics students, educators, and anyone interested in understanding motion dynamics, particularly in scenarios involving elevators and free-falling objects.

Fuzzykatecake
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An open elevator is moving with an upward velocity of
0.52ms-1 with an upward acceleration of 2.4ms-2. A ball bearing then rolls off the floor with zero horizontal speed. Determine the speeds of ball bearing and elevator 2s after the ball rolls off the floor.

Using v=u+at, speed of ball bearing
Answer given was
v=(-0.52)+(9.81)(2)I don't understand why the acceleration of ball is 9.81 and not acceleration of lift. Shouldn't the acceleration of ball be the same as lift as they are in contact?
 
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What do you think 'flier' refers to? (This is a genuine question, I don't know what it means here.) My guess is it means it rolls out of the elevator.
 
haruspex said:
What do you think 'flier' refers to? (This is a genuine question, I don't know what it means here.) My guess is it means it rolls out of the elevator.
I am so sorry! It's floor!
 
Fuzzykatecake said:
I am so sorry! It's floor!
So does that resolve your question?
 
haruspex said:
So does that resolve your question?
Wait.. Are u saying that the ball rolls OUT of the elevator and is free falling and that's why the a is 9.81. But it still has the upward velocity of lift.. But how is it possible?
 
When it rolls out of the lift, it is initially still traveling with an upward velocity of 0.52 m/s. It is then subjected to a downward acceleration of 9.8 m/s2.

Chet
 
Now I get it thanks:)
 

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