Kinetic energy is formed when the object is in motion.
Potential energy is the energy that is formed relative to others.
One of the example is Corn flour factory.
Corn turned into flour by a windmill that moved by the waterfall. Movement of the mill is relative to the power given by waterfall (potential energy) and the spinning crushes the corn into flour (kinetic energy)
You can calculate potential energy by:
U = m.g.h
Where, U = potential energy
m = mass
g = acceleration due to gravity
h = height
Hope this helps!
Answer:
The number of bright fringes per unit width on the screen is, 
Explanation:
If d is the separation between slits, D is the distance between the slit and the screen and 
is the wavelength of the light. Let x is the number of bright fringes per unit width on the screen is given by :
is the wavelength
n is the order
If n = 1,
So, the the number of bright fringes per unit width on the screen is 
. Hence, the correct option is (B).
There are three forces acting on the book.
1. Force due to gravity
2. Force exerted downward by the hamster
3. Normal Force in reaction to the downward forces
Since the book is not moving, the net force is zero. The summation of all forces must be zero. Then we could find the normal force which is unknown (denoted as x).
∑F = -(4 kg)(9.81 m/s2) - 3 N + x =0
∑F = -39.24 N - 3N + x =0
x = 42 N
Therefore, the normal force is 42 N.
