<span>The correct answer is B - Light can travel in a vacuum, and its speed is constant if the source is moving or stationary.</span>
Law of universal gravitation:
F = GMm/r²
F = gravitational force, G = gravitational constant, M & m = masses of the objects, r = distance between the objects
F is proportional to both M and m:
F ∝ M, F ∝ m
F is proportional to the inverse square of r:
F ∝ 1/r²
Calculate the scaling factor of F due to the change in M:
k₁ = 2M/M = 2
Calculate the scaling factor of F due to the change in m:
k₂ = 2m/m = 2
Calculate the scaling factor of F due to the change in r:
k₃ = 1/(4r/r)² = 1/16
Multiply the original force F by the scaling factors to obtain the new force:
Fk₁k₂k₃
= F(2)(2)(1/16)
= F/4
Answer: C. Meyer did not leave gaps while Mendeleev did.
Explanation: Mendeleev's table was table different from Meyer's table because Meyer did not leave gaps while Mendeleev did.
Answer:
The velocity will be v = 22.1[m/s]
Explanation:
We can solve this problem by using the principle of energy conservation, where potential energy is converted to kinetic energy. For this problem we will take the point with maximum potential energy when the body is 25 [m] high. By the time the height is zero, the potential energy will have been transformed into kinetic energy, and we can find the velocity of the body.
![Ep = m*g*h\\where:\\m = mass = 88.2[kg]\\h = elevation = 25[m]\\g = gravity = 9.81 [m/s^2]\\Ep = 88.2*25*9.81 = 21631.05[J]\\](https://tex.z-dn.net/?f=Ep%20%3D%20m%2Ag%2Ah%5C%5Cwhere%3A%5C%5Cm%20%3D%20mass%20%3D%2088.2%5Bkg%5D%5C%5Ch%20%3D%20elevation%20%3D%2025%5Bm%5D%5C%5Cg%20%3D%20gravity%20%3D%209.81%20%5Bm%2Fs%5E2%5D%5C%5CEp%20%3D%2088.2%2A25%2A9.81%20%3D%2021631.05%5BJ%5D%5C%5C)
Now we know that the energy will be transformed.
![Ek=Ep\\Ek=0.5*m*v^{2} \\where:\\v=velocity [m/s]\\v=\sqrt{\frac{Ek}{0.5*m} } \\v=\sqrt{\frac{21631.05}{0.5*88.2} } \\v=22.14[m/s]](https://tex.z-dn.net/?f=Ek%3DEp%5C%5CEk%3D0.5%2Am%2Av%5E%7B2%7D%20%5C%5Cwhere%3A%5C%5Cv%3Dvelocity%20%5Bm%2Fs%5D%5C%5Cv%3D%5Csqrt%7B%5Cfrac%7BEk%7D%7B0.5%2Am%7D%20%7D%20%5C%5Cv%3D%5Csqrt%7B%5Cfrac%7B21631.05%7D%7B0.5%2A88.2%7D%20%7D%20%5C%5Cv%3D22.14%5Bm%2Fs%5D)
