Force, mass, acceleration, kinetic energy

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SUMMARY

The discussion centers on the relationship between force, mass, acceleration, and kinetic energy, specifically addressing a common misconception. When a 1 kg mass is subjected to a constant force of 10 N, it accelerates to approximately 10 m/s in one second, resulting in a kinetic energy of 50 Joules. Conversely, a 10 kg mass under the same force only achieves a kinetic energy of 5 Joules after one second due to the shorter distance traveled, highlighting that work is defined as force times distance, not force times time.

PREREQUISITES
  • Understanding Newton's Second Law of Motion
  • Familiarity with the kinetic energy formula (KE = 1/2 mv²)
  • Basic knowledge of work-energy principles
  • Concept of momentum in physics
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  • Investigate real-world examples of force, mass, and acceleration interactions
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Students of physics, educators teaching mechanics, and anyone interested in understanding the fundamental principles of motion and energy transfer.

Low-Q
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Hi all,

I stumbled into a somewhat odd mathematical problem, so I guess I've overlooked an important detail.
If I have a mass of 1kg on wheels horizontally, and apply 10N of constant force so the mass is accellerating. I assume the velocity of that mass after 1 second is approx 10m/s. Then kinetic energy should be approx 50 Joule. (1/2 (m*v*v)).

Then I have a mass of 10kg on wheels horizontally, and apply 10N of force for one second. Maybe I'm dumb, but it appears to me that the kinetic energy after one second is only 5 Joule. Shouldn't it be 50 Joule?

What have I missed out?

Br. Vidar
 
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Work is force times distance, not force times time. The 10 kg doesn't move so far in 1 s.

Try the same thing with momentum instead of energy, and surprise yourself :rolleyes: !
 
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BvU said:
Work is force times distance, not force times time. The 10 kg doesn't move so far in 1 s.

Try the same thing with momentum instead of energy, and surprise yourself :rolleyes: !
Yeah! Sometimes I stumble in my own brain. Thanks for clearing this up :-)
 
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