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tino4ka555 [31]
2 years ago
7

The standing vertical jump is a good test of an athlete's strength and fitness. The athlete goes into a deep crouch, then extend

s theirlegs rapidly; when theirlegs are fully extended, theyleave the ground and rise to theirhighest height.It is the force of the ground on the athlete during the extension phase that accelerates the athlete to the final speed with which theyleave the ground.A good jumper can exert a force on the ground equal to twice theirweight. If thecrouch is 65 cm deep, how far off the ground do theyrise
Physics
1 answer:
Serga [27]2 years ago
3 0

Answer:

  h = 1.3 m

Explanation:

For this exercise we can use the relationship between work and kinetic energy

          W = Δx = K_f - K₀

in the exercise they indicate that the strength of the athlete is over twice his weight, therefore the ratio of the floor directed upwards has the same value

           F = 2W

           F = 2 mg

the displacement is x = 0.65 m, note that the direction of the force and the displacement is the same and the initial velocity is zero due to being crouched at rest, we substitute

          F x = ½ m v² - 0

         v² = 2 (2mg) x / m

         v = \sqrt{4gx}

     

let's calculate

          v = \sqrt{ 4 \ 9.8 \ 0.65}

          v = 5.05 m / s

already in the air energy is conserved

starting point. Just when it comes off the ground

         Em₀ = K = ½ m v²

final point. When is it at the highest part of the trajectory

          Em_f = U = m g h

          Em₀ = Em_f

          ½ m v² = m g h

           h = ½  \frac{v^2}{g}

let's calculate

           h = ½ 5.05²/9.8

           h = 1.3 m

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<h2>Kinetic energy just before hitting the floor is 324.57 J</h2>

Explanation:

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That is

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We also have equation of motion v² = u² + 2as

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v = 3.13 m/s

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We have kinetic energy = 0.5 x Mass x Velocity²

Substituting

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           Kinetic energy = 324.57 J

Kinetic energy just before hitting the floor is 324.57 J

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3 years ago
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8 0
3 years ago
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Answer:

\boxed {\boxed {\sf D. \ 6.02*10^{23} \ atoms}}

Explanation:

One mole of a substance contains the same amount of representative particles. These particles can be atoms, molecules, ions, or formula units. In this case, the particles are atoms of titanium.

Regardless of the particles, there will always be <u>6.02*10²³</u> (also known as Avogadro's Number) particles in one mole of a substance.

Therefore, the best answer for 1 mole of titanium is D. 6.02*10²³ atoms.

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It shows that the wavelength is inversely proportional to the frequency.

So, higher the frequency, smaller be the wavelength.

So, FM has high frequency than AM, thus, FM has lower wavelength as compared to AM.

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