Question

$The \: kinetic \: energy \: of \: an \: object \: of \: mass \: ‘m' \: moving \: with \: a \: velocity \: of \: 2.5 m/s \: is \: 25J. \: What \: will \: be \: it’s \: kinetic \: energy \: when \: its \: velocity \: is \: increased \: 3 \: times?\ \textless \ br /\ \textgreater \ \: please \: pleazzzzzzzzzz$
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Answer 1

Formerly,

½mv² = 25 J

$\leadsto$ ½ m (2.5 m/s)² = 25 J

$\leadsto$ ½ m × 6.25 m²/s² = 25 kg m²/s²

$\leadsto$ ½ m = 4 kg

$\leadsto$ m = 8 kg

But, now,

½mv'² = ½ (8 kg)(7.5 m/s)² = (4)(56.25) = 225 J.

[Finally, v' = 3v = 3(2.5 m/s) = 7.5 m/s.]