Unlock the Mystery of Kinetic Energy with Expert Guidance - Major Help Needed

In summary, the conversation discusses a problem related to calculating kinetic energy using the formula KE=(1/2)mv^2. The person asking for help is struggling with understanding the concept and converting between units. The conversation also touches on finding the average acceleration.
  • #1
Femme06Fatale
14
0
Kinetic Energy -- Major Help Needed

I'm not even looking for answers ... just for somebody who is really willing to help me out here because I definitely do not understand ANY of this stuff that we're doing right now. Any body, please?
 
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  • #2
What do you need help on?
 
  • #3
Heh .. this is just the first problem of my homework that I entirely DO NOT understand ...

In 1994, Leroy Burrell of the US set what was then a new world record for the me's 100 m run. He ran the 1.00 X 10^2 m distance in 9.85s. Calculate burrelll's kinetic energy, assuming that he ran w/ a constant speed equal to his average speed. Assume his mass was 75.0 kg!

So when I work this all out. .. I got this number such as 3865.08 J ... but that isn't even possible -- I'm so lost :(
 
  • #4
Do you know [tex]KE=(1/2)mv^2[/tex]?
 
  • #5
well, I guess that maybe it could be right ... it is just .. why do I have to answer it w/ it being 3.87 X 10 ^3? that kind of confused me ...
 
  • #6
Actually I just did the problem and I believe your answer is right. Don't take my word for it though.
 
  • #7
Maybe I just need to learn how to become more confident with this stuff ... but I just can't visualize it very well ... any suggestions as to how I can start to really visualize this stuff more? One final question for the time being ... how do I convert from MJ to J?
 
  • #8
You did this right?

[tex]Ke=(1/2)*75kg*v^2[/tex]

[tex]v_{constant}=\frac{100m}{9.85s}=(10.15228426m/s)^2[/tex]

[tex]Ke=(1/2)*75kg*103.0688757[/tex]

[tex]Ke=3865.082839 J[/tex]

Seems right to me
 
  • #9
alright now ... say I'm trying to find the kinetic energy and i have an average speed ... ?
 
  • #10
1 MJ= 1 000 000 J

Maybe you mean an accelerated speed, where you can get the average acceleration:

[tex]a_{average}=\frac{v_2-v_1}{t_s} [/tex]

[tex]v_2[/tex] is the final speed
[tex]v_1[/tex] is the initial speed.
t is time in seconds
 
  • #11
Thank you :)
 

1. What is kinetic energy?

Kinetic energy is the energy an object possesses due to its motion. It is dependent on the mass and velocity of the object.

2. How is kinetic energy calculated?

The formula for calculating kinetic energy is KE = 1/2 mv^2, where m is the mass of the object and v is the velocity.

3. What are some real-life examples of kinetic energy?

Some examples of kinetic energy include a moving car, a swinging pendulum, a thrown ball, and wind.

4. How does kinetic energy relate to potential energy?

Kinetic energy and potential energy are two forms of energy that can be interchanged. For example, a roller coaster has potential energy at the top of a hill and converts it into kinetic energy as it moves down the hill.

5. How does temperature affect kinetic energy?

In most cases, an increase in temperature will result in an increase in kinetic energy. This is because temperature is a measure of the average kinetic energy of particles in a substance. An increase in temperature means an increase in the average speed of particles, resulting in a higher kinetic energy.

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