Force, mass, acceleration, kinetic energy

AI Thread Summary
The discussion revolves around a misunderstanding of kinetic energy calculations in relation to force and mass. A 1kg mass subjected to a 10N force accelerates to approximately 10m/s, resulting in 50 Joules of kinetic energy after one second. In contrast, a 10kg mass under the same force does not achieve the same velocity due to its greater inertia, leading to only 5 Joules of kinetic energy. The key takeaway is that work is defined as force times distance, not force times time, which explains the discrepancy in energy calculations. This highlights the importance of understanding the relationship between force, mass, and acceleration in physics.
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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