Conservation of energy equation

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SUMMARY

The discussion centers on formulating a conservation of energy problem based on the equation provided by the professor: (1/2)(3kg)(7m/s)^2 + 0 + (0.15)(3kg)(9.8m/s^2)(2.0m) = 0 + 0 + T(2.0m). The equation incorporates kinetic energy and gravitational potential energy, with T representing tension in the context of a bungee jumping scenario. The participant proposes a problem involving a 3 kg rabbit named Joe, who bungee jumps from a height, calculating energy at the moment the rope becomes taut. The discussion emphasizes the importance of understanding the roles of kinetic energy, gravitational potential energy, and external forces in energy conservation.

PREREQUISITES
  • Understanding of kinetic energy and its formula: KE = (1/2)mv^2
  • Knowledge of gravitational potential energy and its formula: PE = mgh
  • Familiarity with the concept of tension in physics
  • Basic principles of conservation of energy
NEXT STEPS
  • Explore the concept of energy conservation in mechanical systems
  • Study the role of external forces in energy equations
  • Learn about tension in ropes and its effect on energy calculations
  • Investigate real-world applications of conservation of energy in bungee jumping scenarios
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and energy conservation, as well as educators looking for practical examples to illustrate these concepts.

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Homework Statement


My professor has provided me with an equation, and my task is to write a conservation of energy problem whose solution would produce said equation.

Here is the equation:
(1/2)(3kg)(7m/s)^2 + 0 + (0.15)(3kg)(9.8m/s^2)(2.0m) = 0 + 0 + T(2.0m)


Homework Equations


Work internal = 0
W = F . d


The Attempt at a Solution



A 3 kilogram rabbit who lives on a planet with 15% the gravity of that of earth. During his daily run, while on top of a 2.0m hill, his speed peaks at 7m/s. At this point, what is his total energy?

This question accounts for the first two terms of the equation, both of the left side. I am still left wondering, however, what the T on the right side stands for. Note that this is a thermodynamics class; however, we have had less than an hour of class and have yet to learn any thermodynamics. Could T stand for temperature here? If so, how can I use this value in terms of energy?
 
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Temperature times length does not have the proper units (of course, all the terms should have units of energy, i.e. Joules).
Force times length, however, does. One word that comes to mind is tension... ?
 
ah hah.

Suppose my problem looks like this, then:

A 3 kilogram rabbit named Joe lives on a planet with 15% the gravity of that of earth. Joe loves to bungie jump. During one of his more adventurous endeavors, Joe ties a rope to himself and a bridge, leaving exactly 2m worth of slack. Joe calculates his initial jumping height such that the rope will become taught when he reaches 7m/s; his calculations report that he will be 2m above the ground at this time. Write a conversation of energy equation describing the rabbit's energy when the rope becomes taught.

Does this make sense? The tension on the rope is acting external to the system of the rabbit. Since the rabbit is 2m above the ground, and since gravitational potential energy is mgh, that should check out as well. What do you guys think?
 

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