An example of a balanced force would be a book sitting on a shelf untouched.
Isaac Newton’s First Law of Motion states that an object at motion stays in motion, and an object at rest stays at rest until acted on by an unbalanced force. A book sitting still is an example of a balanced force because nothing is acting on it; its potential energy is stored while it’s at rest. For this book to become an unbalanced force, an outside force would have to occur (i.e pushing the book or dropping it) that causes it to not be in a state of stillness.
Answer:
25.3 ft
Explanation:
The illustration of the problem is shown the attached image.
The length of the ladder can be calculated using the Pythagoras theorem:

The hypotenuse is the length of the ladder.

........1
Triangle ABC is similar to triangle AEF, hence:

BC =
.................2
Substitute 2 into 1
=
+ 
Let AE = x
= 
= 
Minimize L with respect to x.
2
= 
=
Answer:
4.1 eV
Explanation:
Kinetic energy, K = 0.8 eV = 0.8 x 1.6 x 10^-19 J = 1.28 x 10^-19 J
wavelength, λ = 253.5 nm = 253.5 x 10^-9 m
According to the Einstein energy equation

Where, E be the energy incident, Wo is the work function and K is the kinetic energy.
h = 6.634 x 10^-34 Js
c = 3 x 10^8 m/s

So, the work function, Wo = E - K
Wo = 7.85 x 10^-19 - 1.28 x 10^-19
Wo = 6.57 x 10^-19 J
Wo = 4.1 eV
Thus, the work function of the metal is 4.1 eV.
Answer:
35.20 m
Explanation:
By the law of conservation of energy we have,



where m= mass of the skier, h= 3.00 m
D= horizontal distance=13.9 m
H= maximum height attained
Also, the horizontal distance covered by the skier is
D=vt


thus, height H in terms of D is given by


H=35.20 m