Question

What is the power output in watts of a 60 kg sprinter who accelerates from rest to 10 m/s in 3 s ?

Answer 1

Mass of the sprinter = m = 60 kg

Initial velocity = u = 0

Final Velocity = v= 10 m/s

Time = t = 3 s

Power = P =

$\frac{energy \: aquired}{time} \\ \\ = \frac{ \frac{1}{2}m {v}^{2} }{t} \\ \\ = \frac{m {v}^{2} }{2t} \\ \\ = \frac{60 \times {10}^{2} }{2 \times 3} \\ \\ = \: 1000 \: w$

Answer 2

$Hey\:!!..$

The answer goes here....

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Given,

m = 60 kg

v = $10\:{ms}^{-1}$

u = $0\:{ms}^{-1}$

t = 3 sec

By using the equation -

⇒ $v$ = $u+at$

⇒ $10$ = $0+a\times 3$

⇒ a = $\frac{10}{3}$

Now, the distance -

⇒ $s$ = $ut+\frac{1}{2}{at}^{2}$

⇒ $s$ = $0\times 3+\frac{1}{2}\times\frac{10}{3}{at}^{2}$

⇒ $s$ = $15\:m$

Now, the work done -

⇒ $w$ = $Fs$

⇒ $w$ = $60\times \frac{10}{3}\times 15$

⇒ $w$ = $3000\:J$

Also, we know that -

⇒ $P$ = $\frac{w}{t}$

⇒ $P$ = $\frac{3000}{3}$

⇒ $P$ = $1000\:w$

So, the power output in watts will be 1000 w.

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Thanks !!..