-- The position of the sun was originally the primary influence in determining
when people went to sleep and when they woke up. Although it no longer
directly influences us, that pattern is so deeply ingrained in our make-up
that our behavior still largely coincides with the positions of the sun.
-- The position of the Moon was originally the primary influence in determining
the cycle of human female physiology. Although it no longer directly influences
us, that pattern is so deeply ingrained in human make-up that the female cycle
still largely coincides with the positions of the Moon.
F = 750 N (Force)
d = 10 m (displacement
)
t = 25 s (time)
L = ? (Mechanical work
) = (Energy)
P = ? (Power)
Solve:
L = F × d = 750 × 10 = 7500 Joules
P = L / t = 7500 / 25 = 300 Watts
Answer:
Explanation:
<u></u>
<u>1. Formulae:</u>
Where:
- E = kinetic energy of the particle
- λ = de-Broglie wavelength
- m = mass of the particle
- v = speed of the particle
- h = Planck constant
<u><em>2. Reasoning</em></u>
An alha particle contains 2 neutrons and 2 protons, thus its mass number is 4.
A proton has mass number 1.
Thus, the relative masses of an alpha particle and a proton are:
![\dfrac{m_\alpha}{m_p}=4](https://tex.z-dn.net/?f=%5Cdfrac%7Bm_%5Calpha%7D%7Bm_p%7D%3D4)
For the kinetic energies you find:
![\dfrac{E_\alpha}{E_p}=\dfrac{m_\alpha \times v_\alpha^2}{m_p\times v_p^2}](https://tex.z-dn.net/?f=%5Cdfrac%7BE_%5Calpha%7D%7BE_p%7D%3D%5Cdfrac%7Bm_%5Calpha%20%5Ctimes%20v_%5Calpha%5E2%7D%7Bm_p%5Ctimes%20v_p%5E2%7D)
![\dfrac{1eV}{4eV}=\dfrac{4\times v_\alpha^2}{1\times v_p^2}\\\\\\\dfrac{v_p^2}{v_\alpha^2}=16\\\\\\\dfrac{v_p}{v_\alpha}=4](https://tex.z-dn.net/?f=%5Cdfrac%7B1eV%7D%7B4eV%7D%3D%5Cdfrac%7B4%5Ctimes%20v_%5Calpha%5E2%7D%7B1%5Ctimes%20v_p%5E2%7D%5C%5C%5C%5C%5C%5C%5Cdfrac%7Bv_p%5E2%7D%7Bv_%5Calpha%5E2%7D%3D16%5C%5C%5C%5C%5C%5C%5Cdfrac%7Bv_p%7D%7Bv_%5Calpha%7D%3D4)
Thus:
![\dfrac{m_\alpha}{m_p}=4=\dfrac{v_p}{v__\alpha}](https://tex.z-dn.net/?f=%5Cdfrac%7Bm_%5Calpha%7D%7Bm_p%7D%3D4%3D%5Cdfrac%7Bv_p%7D%7Bv__%5Calpha%7D)
![m_\alpha v_\alpha=m_pv_p](https://tex.z-dn.net/?f=m_%5Calpha%20v_%5Calpha%3Dm_pv_p)
From de-Broglie equation, λ = h/(mv)
![\dfrac{\lambda_p}{\lambda_\alpha}=\dfrac{m_\lambda v_\lambda}{m_pv_p}=\dfrac{1}{1}=1:1](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Clambda_p%7D%7B%5Clambda_%5Calpha%7D%3D%5Cdfrac%7Bm_%5Clambda%20v_%5Clambda%7D%7Bm_pv_p%7D%3D%5Cdfrac%7B1%7D%7B1%7D%3D1%3A1)