|MadSci Network: Physics|
At school I did a simple classroom experiment to demonstrate how gravitational potential energy is converted into kinetic energy when a dynamics trolley of a certain mass is released from the top of a ramp. The speed of the dynamics trolley as it moved down the ramp was detected using speed sensors. After completing the experiment I did some calculations to determine the gravitational potential energy of the trolley at the start of the experiment (at the top of the ramp before being released) and the kinetic energy it had as it passed through the speed sensors. I then used these 2 figures to work out the efficiency of the transfer of gravitational potential energy into kinetic energy. I found from my calculations that the conversion was not 100% efficient. My question is, how was energy lost during this conversion? Was this energy lost due to friction between the wheels of the dynamics trolley and surface of the ramp? If this is the case, was this energy lost in the form of heat energy? Did this friction cause both the wheels of the trolley and the surface of the ramp to gain heat (or just one of the aforementioned)? Where does this heat energy then go - is it simply lost to the surroundings or can it somehow be usefully reused/recycled? I also wonder whether energy could have been lost during the conversion of gravitational potential energy into kinetic energy due to air resistance? I believe that air resistance can reduce the speed of a moving object (thus it is useful to streamline the shape of a racing car) but am unsure whether this effectively reduces its amount of kinetic energy. Would one or both of these factors (+ any others) be responsible for the inefficient conversion of gravitational potential energy into kinetic energy? If, in fact, air resistance is also a reason for energy loss, what happens to this lost energy? Is it perhaps lost as heat energy and warms the surroundings? Thank you
Re: How can energy be lost during energy conversions?
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