Physics, 26.07.2019 00:00 falgunim4

A56 kg sprinter, starting from rest, runs 49 m in 7.0 s at constant acceleration. what is the sprinter's power output at 2.0 s, 4.0 s, and 6.0 s

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Answer from: 214578

The sprinter's power output at 2.0 is 2,744 J/s.

The sprinter's power output at 4.0 s is 1,372 J/s.

The sprinter's power output at 6.0 s is 914.67 J/s.

The given parameters;

mass of the sprinter, m = 56 kginitial velocity of the sprinter, u = 0distance covered by the sprinter, s = 49 mtime of motion of the sprinter, t = 7.0 s

The acceleration of the sprinter is calculated as follows;

s = u + ¹/₂at²

49 = 0 + (7² x 0.5)a

49 = 24.5a

a = 2 m/s²

The force exerted by the sprinter is calculated as follows;

F = ma

F = 56 x 2

F = 112 N

The sprinter's power output at 2.0 s;

$Power \ 0utput= \frac{Energy}{time} = \frac{F \times d}{t} \\\\Power \ 0utput= \frac{112 \times 49}{2} = 2,744 \ J/s$

The sprinter's power output at 4.0 s;

$Power \ 0utput= \frac{Energy}{time} = \frac{F \times d}{t} \\\\Power \ 0utput= \frac{112 \times 49}{4} = 1,372 \ J/s$

The sprinter's power output at 6.0 s;

$Power \ 0utput= \frac{Energy}{time} = \frac{F \times d}{t} \\\\Power \ 0utput= \frac{112 \times 49}{6} = 914.67 \ J/s$

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Answer from: 20calzoy

The sprinter is in uniform accelerated motion, and its initial velocity is zero, so the relationship betwen space (S) and time (t) is
$S= \frac{1}{2} a t^2$
where a is the acceleration. Using the data of the problem, we can find a:
$a= \frac{2S}{t^2} = \frac{2 \cdot 49 m}{(7.0 s)^2} =2.0 m/s^2$
So now we can solve the 3 parts of the problem.

a) power output at t=2.0 s
The velocity at t=2.0 s is
v(t)=at=(2.0 m/s^2)(2.0 s)=4.0 m/s

the kinetic energy of the sprinter is
$K= \frac{1}{2} mv^2= \frac{1}{2}(56 kg)(4.0 m/s)^2=448 J$

and so the power output is
$P= \frac{E}{t} = \frac{448 J}{2.0 s} =224 W$

b) power output at t=4.0s
The velocity at t=4.0 s is
v(t)=at=(2.0 m/s^2)(4.0 s)=8.0 m/s

the kinetic energy of the sprinter is
$K= \frac{1}{2} mv^2= \frac{1}{2}(56 kg)(8.0 m/s)^2=1792 J$

and so the power output is
$P= \frac{E}{t} = \frac{1792 J}{4.0 s} =448 W$

c) Power output at t=6.0 s
The velocity at t=2.0 s is
v(t)=at=(2.0 m/s^2)(6.0 s)=12.0 m/s

the kinetic energy of the sprinter is
$K= \frac{1}{2} mv^2= \frac{1}{2}(56 kg)(6.0 m/s)^2=4032 J$

and so the power output is
$P= \frac{E}{t} = \frac{4032 J}{6.0 s} =672 W$

Answer from: Quest

No it doesnt because it can be any number.

Answer from: Quest

answer;

d. are made mostly of liquid

explanation;

-the general composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

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A56 kg sprinter, starting from rest, runs 49 m in 7.0 s at constant acceleration. what is the sprint...

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