Answer:
Maximum Power = 144.3 D
The associated focal length of the lens = 
Explanation:
According to the Lens maker's Formula:

where;
= the refractive index of the medium
and
= radius of curvature on each surface
For a convex lens, The radius of curvature in the front surface will be positive and that of the second surface will be negative . Therefore;

At maximum power

= 
This Implies

Therefore; the power is given by the formula:


= 144.3 D
The right formula to use is: T^2= 2d/g
where T= time taken
d = 12.5m
g = is a constant and is equal to 9.8m/s
therefore, T^2 = 2*12.5/9.8
Using the values above, the time taken for the acorn to reach the ground is 1.59 second
T = 1.59 S
Answer:
F= 134.92 N
Explanation:
Given that
The mass of the moon ,M = 7.4 x 10²² kg
The mass of the man ,m = 79 kg
The radius ,R= 1.7 x 10⁶ m
The force exerted by moon is given as

Now by putting the values in the above equation we get

Therefore the force will be 134.92 N.
F= 134.92 N
The correct answer is creativity
Being kind and helpful in no way helps you develop theories, however, being creative does because creativity leads to ingenuity and testing and trying various things.