# Conservation of energy

## Main Question or Discussion Point

a car(54g)(toy) releases from a high place through a railway to a flat low place. by observation from an experiment, for sure there's some energy lost causing by the friction n drag force. 2nd time i do it, i add some mass(50g) for the car n releases again. i found tat the 2nd car's energy will lose less comparing with 1st car. after i counted the percentage of energy lost, i got tat the 1st car is 60%++ but the 2nd car with bigger mass is 10%++.

By theorectical method, will the energy lost of a bigger mass larger than the small mass object?

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Good question... How is the reletive loss of energy to heat depend on body mass?

I think that if concidering loss to heat via velocity dependent friction (~v), two masses of similar proportions (say a sphere) but of deferent masses moving through similar fluid would reasult in a greater loss of reletive kinetic energy to the smaller ball (under a similar displacemet). I conclude this due to a greater ratio of contact area to mass with the a smaller object. So more contact area would result in a higher constant of friction.

Good question... How is the reletive loss of energy to heat depend on body mass?

I think that if concidering loss to heat via velocity dependent friction (~v), two masses of similar proportions (say a sphere) but of deferent masses moving through similar fluid would reasult in a greater loss of reletive kinetic energy to the smaller ball (under a similar displacemet). I conclude this due to a greater ratio of contact area to mass with the a smaller object. So more contact area would result in a higher constant of friction.
so if the contact surface area(wheel) of both cars are same, what should the result be?