Calculating velocity in regards to the mass and kinetic energy of an object

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SUMMARY

The discussion centers on calculating the velocity of a baseball with a mass of 145 grams and a kinetic energy of 94 joules. The correct formula for velocity is derived from the kinetic energy equation, v = √(2Ek/m). The user initially used an incorrect mass of 0.0145 kg instead of the correct 0.145 kg, leading to an erroneous velocity calculation of 114 m/s instead of the accurate 36 m/s. The conversion factor of 1 J = 1 kg·m²/s² is crucial for understanding the relationship between kinetic energy, mass, and velocity.

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  • Understanding of kinetic energy and its formula
  • Basic knowledge of unit conversions, specifically joules to mass and velocity
  • Familiarity with algebraic manipulation of equations
  • Concept of mass in kilograms for physics calculations
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  • Review the kinetic energy formula and its derivation
  • Practice unit conversions between grams and kilograms
  • Learn about dimensional analysis in physics
  • Explore additional examples of kinetic energy calculations
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Students studying physics, particularly those focusing on mechanics and energy concepts, as well as educators looking for examples of kinetic energy applications.

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Homework Statement



How fast is a baseball with a mass of 145 g traveling if it has 94 J of kinetic energy?

Homework Equations



m = 145 g or 0.0145 kg
Ek = 94 J
v = ?

v = √2Ek/m

The Attempt at a Solution



I get...
v = √2(94)/0.0145 kg
v = √12966
v = 114

But my book says it should be 36 m/s. What am I doing wrong?

It also mentions that I need to recall that 1 J = 1 kg . m^2/s^2 but I am unsure how to incorporate this into the equation or if it is even necessary.
 
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Your mass should be .145 kg.
 
Your mass should be 0.145 kg and not 0.0145kg
 

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