The velocity of shortening refers to the speed of the contraction from
the muscle shortening while lifting a load. The relationship between the
resistance and velocity of shortening is inverse. The greater the
resistance, the shorter the velocity of shortening and the smaller the
resistance, the larger the velocity of shortening.
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Answer:
Four fundamental forces are gravitational, electromagnetic, strong, and weak.
Explanation:
The gravitational and electromagnetic interactions, which produce significant long-range forces whose effects can be seen directly in everyday life and the strong and weak interactions, which produce forces at minuscule, subatomic distances and govern nuclear interactions.
Systemic circulation is between the heart and the rest of the body. Therefore arteries and veins are needed.
The kinetic energy as measured in the Earth reference frame is 6.704*10^22 Joules.
To find the answer, we have to know about the Lorentz transformation.
<h3>What is its kinetic energy as measured in the Earth reference frame?</h3>
It is given that, an alien spaceship traveling at 0.600 c toward the Earth, in the same direction the landing craft travels with a speed of 0.800 c relative to the mother ship. We have to find the kinetic energy as measured in the Earth reference frame, if the landing craft has a mass of 4.00 × 10⁵ kg.
![V_x'=0.8c\\V=0.6c\\m=4*10^5kg](https://tex.z-dn.net/?f=V_x%27%3D0.8c%5C%5CV%3D0.6c%5C%5Cm%3D4%2A10%5E5kg)
- Let us consider the earth as S frame and space craft as S' frame, then the expression for KE will be,
![KE=m_0c^2=\frac{mc^2}{1-(\frac{v_x^2}{c^2} )}](https://tex.z-dn.net/?f=KE%3Dm_0c%5E2%3D%5Cfrac%7Bmc%5E2%7D%7B1-%28%5Cfrac%7Bv_x%5E2%7D%7Bc%5E2%7D%20%29%7D)
- So, to
find the KE, we have to find the value of speed of the approaching landing craft with respect to the earth frame. - We have an expression from Lorents transformation for relativistic law of addition of velocities as,
![V_x'=\frac{V_x-V}{1-\frac{VV_x}{c^2} } \\thus,\\V_x=V_x'(1-\frac{VV_x}{c^2} )+V](https://tex.z-dn.net/?f=V_x%27%3D%5Cfrac%7BV_x-V%7D%7B1-%5Cfrac%7BVV_x%7D%7Bc%5E2%7D%20%7D%20%5C%5Cthus%2C%5C%5CV_x%3DV_x%27%281-%5Cfrac%7BVV_x%7D%7Bc%5E2%7D%20%29%2BV)
- Substituting values, we get,
![V_x=0.8c(1-\frac{0.8c*0.6c}{c^2} )+0.6c=(0.8c*0.52)+0.6c=1.016c](https://tex.z-dn.net/?f=V_x%3D0.8c%281-%5Cfrac%7B0.8c%2A0.6c%7D%7Bc%5E2%7D%20%29%2B0.6c%3D%280.8c%2A0.52%29%2B0.6c%3D1.016c)
![KE=\frac{4*10^5*(3*10^8)^2}{\sqrt{1-\frac{(1.016c)^2}{c^2} } } =\frac{1.2*10^{22}}{0.179}=6.704*10^{22}J](https://tex.z-dn.net/?f=KE%3D%5Cfrac%7B4%2A10%5E5%2A%283%2A10%5E8%29%5E2%7D%7B%5Csqrt%7B1-%5Cfrac%7B%281.016c%29%5E2%7D%7Bc%5E2%7D%20%7D%20%7D%20%3D%5Cfrac%7B1.2%2A10%5E%7B22%7D%7D%7B0.179%7D%3D6.704%2A10%5E%7B22%7DJ)
Thus, we can conclude that, the kinetic energy as measured in the Earth reference frame is 6.704*10^22 Joules.
Learn more about frame of reference here:
brainly.com/question/20897534
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