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A block of mass *m* = 1 kg moving on a horizontal surface with speed *v* * *_{i} = 2 ms^{–1} enters a rough patch ranging from *x* = 0.10 m to *x* = 2.01 m. The retarding force *F*_{r} _{ }on the block in this range is inversely proportional to *x* over this range

${F}_{r}=\frac{k}{x}$ for 0.1 <* x* < 2.01 m

= 0 for *x* < 0.1 m and *x* > 2.01 m

where *k* = 0.5 J. What is the final K.E. and speed *v*_{f} _{ } of the block as it crosses the patch?

$\nu $

_{i}

_{r}

_{f}

_{ }

Example of pradeep, try to see everything in books, rather asking it from others....