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3 years ago

How much kinetic energy does a person of mass 50kg running at 3m/s have? Provide

Physics

1 answer:

ddd [48]3 years ago

4 0

Answer:

0.225 KJ kinetic energy is used for a person of mass 50 Kg running at speed of 3 m/s.

Explanation:

Given:

mass = 50 kg

velocity = v = 3 m/s

To Find :

Kinetic energy = ?

Solution:

Kinetic energy of an object is the energy that it possesses due to its motion.

The formula for kinetic energy is given as

$\textrm{kinetic energy} = \frac{1}{2}\times mass\times velocity^{2}\\= \frac{1}{2}\times m\times v^{2}\\= \frac{1}{2}\times 50\times 3^{2}\\= 25\times 9\\= 225\ Joules.$

But we required kinetic energy in KiloJoules i.e KJ

1 K = 1000 = $10^{3}$

$\textrm{kinetic energy} = 225\ J\\= 0.225\times 1000\\= 0.225 \times 10^{3}\\= 0.225\ KJ$

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A 10-foot ladder is leaning straight up against a wall when a person begins pulling the base of the ladder away from the wall at

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Answer:

$y = 4.36$

Explanation:

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Also:

Let $x = distance\ from\ the\ base\ of\ the\ ladder$

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When the ladder leans against the wall, it forms a triangle and the length of the ladder forms the hypotenuse.

So, we have:

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When the base is 9ft from the wall, this means that:

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Substitute 9 for x and 10 for L in $L^2 = x^2 + y^2$

$10^2 = 9^2 + y^2$

$100 = 81 + y^2$

Make $y^2$ the subject

$y^2 = 100 - 81$

$y^2 = 19$

Make y the subject

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$y = 4.36$

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3 years ago

A guitar string has a linear density of 8.30 ✕ 10−4 kg/m and a length of 0.660 m. the tension in the string is 56.7 n. when the

Sedbober [7]

Ans: Beat Frequency = 1.97Hz

Explanation:
The fundamental frequency on a vibrating string is

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<span>here, T=Tension in the string=56.7N,
L=Length of the string=0.66m,
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Plug in the values in Equation (A)

<span>so </span> $f = \sqrt{ \frac{56.7}{4*5.48*10^{-4}*0.66} }$ <span> = 197.97Hz </span>

<span>the beat frequency is the difference between these two frequencies, therefore:
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3 years ago

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Answer:

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3 years ago

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