-friction Is Independant Of Surface Area-

----friction Is Independant Of Surface Area------

>> can anyone tel y friction is independant of surface area/length ......

thx an regards,

arun

thank u sir ...to rephrase my question to get a still better explnation (wit regard to myself) .....

>> why is rolling better than sliding ??

thx and regards,

arun

arildno
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Rolling is better than sliding, because in rolling, friction merely CONVERTS translational kinetic energy into rotational energy without net energy loss, wheres in sliding, the object loses kinetic energy.

thank u sir,
my question is why does while sliding ,kinetic energy is lost as (friction) heat energy....why not while rollin????

thanks and regards,

arun

arildno
Let S be a system of N particles, and let $\vec{F}_{i}$ be the net force acting upon the i'th particle.
Thus, if $K_{i}$ is the kinetic energy of the i'th particle, the rate of change is:
$$\frac{dK_{i}}{dt}=\frac{d}{dt}(\frac{m_{i}\vec{v}_{i}^{2}}{2})=m_{i}\vec{a}_{i}\cdot\vec{v}_{i}=\vec{F}_{i}\cdot\vec{v}_{i}$$
where $\vec{v}_{i},\vec{a}_{i},m_{i}$ is the i'th particle's velocity, acceleration and mass, respectively.