Explanation:
First we need to find the acceleration due to gravity on the planet. The wrench took 0.809 s to fall from a height of 4.50 m so we can use the equation
Solving for g, we get
Recall that the acceleration due to gravity on a planet's surface can be written as
We can express the mass of the planet 
in terms of its density 
as follows:
The expression for g then becomes
Solving for 
we get
![\:\:\:\:\:\:\:= \left[\dfrac{3(13.8\:\text{m/s}^2)}{4\pi (6.674×10^{-11}\:\text{Nm}^2\text{/kg}^2)(5500\:\text{kg/m}^3)}\right]](https://tex.z-dn.net/?f=%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%5C%3A%3D%20%5Cleft%5B%5Cdfrac%7B3%2813.8%5C%3A%5Ctext%7Bm%2Fs%7D%5E2%29%7D%7B4%5Cpi%20%286.674%C3%9710%5E%7B-11%7D%5C%3A%5Ctext%7BNm%7D%5E2%5Ctext%7B%2Fkg%7D%5E2%29%285500%5C%3A%5Ctext%7Bkg%2Fm%7D%5E3%29%7D%5Cright%5D)
Answer:
The path difference between the two waves should be one-half of a wavelength
Explanation:
When two beams of coherent light travel different paths, arriving at point P. If the maximum destructive interference is to occur at point P , then the condition for it is that the path difference of two beams must be odd multiple of half wavelength. Symbolically
path difference = ( 2n+1 ) λ / 2
So path difference may be λ/2 , 3λ/ 2, 5λ/ 2 etc .
Hence right option is
The path difference between the two waves should be one-half of a wavelength.
If the friction and air resistance was 75N and Elaine was traveling with a force of 75N the forces would cancel out. Elaine's bike would not be moving and all the forces would be balanced
The correct answer would be D.
