Explanation:
Trees, because of their height, are natural lightning rods. Electricity seeks the path of least resistance, and the moisture inside a tree is a much better conductor than air. This means a tree provides the preferred path for lightning to reach the ground.
Answer:
distance between the dime and the mirror, u = 0.30 m
Given:
Radius of curvature, r = 0.40 m
magnification, m = - 2 (since,inverted image)
Solution:
Focal length is half the radius of curvature, f = 
f = 
Now,
m = - 
- 2 = -
= 2 (2)
Now, by lens maker formula:


v =
(3)
From eqn (2):
v = 2u
put v = 2u in eqn (3):
2u = 
2 = 
2(u - 0.20) = 0.20
u = 0.30 m
Since there is no friction between the ladder and the wall, there can be no vertical force component. That's the tricky part ;)
So to find the weight, divide the 100N <em>normal</em> force by earths gravitational acceleration, 9.8m/s^2

Then;
Draw an arrow at the base of the ladder pointing towards the wall with a value of 30N, to show the frictional force.
The point obviously is in the 3rs quadrant
So
စ= tan^-1( y/x)-180
စ= -89.7°