Answer:
Correct answer letter b.
Explanation:
When the book is on the top shelf of the bookcase, it just only gravitational potential energy, due to the gravitational field and the kinetic energy at this point is zero because the book is at rest.
Now, when the book starts falling, all the potential energy will transform into the kinetic energy. It happens, thanks to the conservation of the energy,that says energy can neither be created nor destroyed, energy can only be transferred or changed from one form to another.
Let's recall that the gravitational potential energy depends on the object's position, so when the book falls, the magnitude of the position decreases and the speed of this object increases.
Therefore, the potential energy of the book decreases as kinetic energy increases.
Correct answer letter b.
I hope it helps you!
Answer:
thinnest soap film is 206.76 nm
Explanation:
Given data
wavelength = 550 nm
index of refraction n = 1.33
to find out
What is the thinnest soap film
solution
we have wavelength λ = 550 nm
that is λ = 550 × 
m
and n = 1.3
we will find the thickness of soap film as given by formula that is
thickness = λ/2n
thickness = 550 × / 2(1.33)
thickness = 206.76 × m
thinnest soap film is 206.76 nm
Answer:
Explanation:
Given that,
The initial speed of a car, u = 0
Time, t = 18 s
Distance, d = 390 m
We need to find the acceleration of the car. Let it is a. Using the second equation of motion to find it.
or
So, the acceleration of the car is 
.
By heat or change in matter,
there can be different reactions that create heat (like exothermic or endothermic reactions)
or movement can give off energy too,
energy is basically just heat
I sort of understand but what does it mean by.... Another?
