Solving Kinetic Energy: Mass, Velocity, and Jogger's Speed

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SUMMARY

The discussion focuses on calculating the kinetic energy of a continent and a jogger using the kinetic energy formula KE = 0.5 * m * V^2. The continent, with a mass density of 2680 kg/m³, has dimensions of 4200 km on each side and a depth of 32 km, resulting in a mass of approximately 3.58 x 10^14 kg. Its kinetic energy, calculated from its average speed of 4.8 cm/year, is approximately 1.03 x 10^10 J. A jogger with a mass of 75 kg has the same kinetic energy as the continent, leading to a calculated velocity of approximately 5.73 m/s.

PREREQUISITES
  • Kinetic Energy Equation (KE = 0.5 * m * V^2)
  • Mass Density Calculation (Density = mass/volume)
  • Volume Calculation for Rectangular Prisms
  • Unit Conversion (from cm/year to m/s)
NEXT STEPS
  • Study the implications of mass density in kinetic energy calculations
  • Explore advanced applications of the kinetic energy formula in physics
  • Learn about unit conversions in physics, particularly for speed
  • Investigate how kinetic energy varies with different masses and velocities
USEFUL FOR

Students in physics, educators teaching mechanics, and anyone interested in applying kinetic energy concepts to real-world scenarios.

anglum
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kinetic energy?

a continent is 4200 km on a side and 32 km deep

its mass density is 2680 kg/m^3
it is moving at an avg speed of 4.8cm/year

what is its mass? answer in units of J

what is its kinetic energy? answer in units of J

a jogger with mass 75kg has the same kinetic energy as the continent... what is his velocity?? answer in units of m/s


i know the KE equation is KE = .5 * m * V^2

i am stuck on what my steps are with this problem... i know if i solve the first part the 2nd and 3rd parts will be easy becuz i plug them into the KE equation
 
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to find the mass of the contintent i would take

Density = mass/volume

2680kg/m^3 = mass / (42000000m * 4200000m * 32000m)

and then solve for mass and that gives me the mass in kg?
 
yes...exactly...then plug in for KE equation
 

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