Question

Qestion 3 please. I need it soon . My exams tomorrow

Answer 1

$\huge\mathfrak\red{Answer}$

WHAT IS WORK?

WORK DONE IS ACTUALLY THE DOT PRODUCT OF FORCE TIME DISPLACEMENT. AND BE SURE THAT THE DIRECTION OF FORCE AND THAT OF DISPLACEMENT IS SAME IF IN SOME CASES THE DIRECTION IS DIFFERENT THAN WHAT YOU SHOULD DO IS GIVE BELOW....

$suppose \: force \:and \: displacement \\ are \: suspended \: at \: an \: angle \: of \: \alpha \\ than \: we \: should \: write \: work \: done \\ as \: dw = f.dr \cos \alpha \\ \\ where \: f \: is \: the \: force \: \\ dr \: is \: the \: small \: displacement \\ dw \: is \: the \: small \: work$

THE CASE U ASKED FOR IS THE SIMILAR TO THAT WE DISCUSSED.

$angle \: between \: \frac{m {v}^{2} }{r} \: and \: circumference \\ is \: \frac{\pi}{2} \\ \\ so \: work \: done = f.dr \cos \alpha \\ work \: done = \frac{m {v}^{2} }{r} \times dr \times \cos( \frac{\pi}{2} ) \\ work \: done = \frac{m {v}^{2} }{r} \times dr \times 0 \\ \\ work \: done = 0$