Calculating Kinetic Energy & Speed of a Thrown Yo-Yo: Physics Problem Help

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SUMMARY

The discussion focuses on calculating the kinetic energy and speed of a yo-yo thrown down a string, with specific parameters provided: a rotational inertia of 820 g·cm², a mass of 115 g, an axle radius of 3.9 mm, and an initial speed of 0.8 m/s. Key calculations include determining the time to reach the end of the 120 cm string, total kinetic energy, translational speed, translational kinetic energy, rotational speed, and rotational kinetic energy. The problem assumes an ideal scenario with no slippage and an infinitely thin, non-stretching string.

PREREQUISITES
  • Understanding of rotational inertia and its impact on motion
  • Familiarity with the concepts of translational and rotational kinetic energy
  • Knowledge of basic kinematics and energy conservation principles
  • Ability to perform calculations involving angular velocity and linear speed
NEXT STEPS
  • Calculate the time taken for the yo-yo to reach the end of the string using kinematic equations
  • Determine the total kinetic energy at the end of the string using the formula KE = 1/2 mv² + 1/2 Iω²
  • Explore the relationship between translational speed and rotational speed using the formula v = rω
  • Investigate energy distribution between translational and rotational kinetic energy in similar systems
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Students studying physics, educators teaching mechanics, and anyone interested in understanding the dynamics of rotational motion and energy conservation in systems like yo-yos.

matt62010
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yo you physics problem, please help!

A yo-yo has a rotational inertia of 820 g·cm2 and a mass of 115 g. Its axle radius is 3.9 mm and its string is 120 cm long. The yo-yo is thrown so that its its initial speed down the string is 0.8 m/s.
(a) How long does the yo-yo take to reach the end of the string?
(b) As it reaches the end of the string, what is its total kinetic energy?
J
(c) As it reaches the end of the string, what is its translational speed?
m/s
(d) As it reaches the end of the string, what is its translational kinetic energy?
J
(e) As it reaches the end of the string, what is its rotational speed?
rad/s
(f) As it reaches the end of the string, what is its rotational kinetic energy?
J
Can someone please explain how to do this?
 
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Assume the string is infinitely thin, doesn't stretch, and no slippage. Compute the energy gain from decrease in height and figure out how this increase is distributed between angular and linear energy.
 

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