Answer:
The dimensionality of B is <em>length</em> per cubic <em>time</em>.
Explanation:
Units for displacement and time are <em>length</em> ![[L]](https://tex.z-dn.net/?f=%5BL%5D)
and <em>time</em> ![[T]](https://tex.z-dn.net/?f=%5BT%5D)
, respectively. Then, formula can be tested for dimensional analysis as follows:
![[L] = B\cdot [T]^{3}](https://tex.z-dn.net/?f=%5BL%5D%20%3D%20B%5Ccdot%20%5BT%5D%5E%7B3%7D)
Now, let is clear 
to determine its units:
![B = \frac{[L]}{[T]^{3}}](https://tex.z-dn.net/?f=B%20%3D%20%5Cfrac%7B%5BL%5D%7D%7B%5BT%5D%5E%7B3%7D%7D)
The dimensionality of B is <em>length</em> per cubic <em>time</em>.
Answer:
According to the travellers, Alpha Centauri is <em>c) very slightly less than 4 light-years</em>
<em></em>
Explanation:
For a stationary observer, Alpha Centauri is 4 light-years away but for an observer who is travelling close to the speed of light, Alpha Centauri is <em>very slightly less than 4 light-years. </em>The following expression explains why:
v = d / t
where
- v is the speed of the spaceship
- d is the distance
- t is the time
Therefore,
d = v × t
d = (0.999 c)(4 light-years)
d = 3.996 light-years
This distance is<em> very slightly less than 4 light-years. </em>
Answer:
Let the mass of the book be "m", acceleration due to gravity be "g", velocity be "v" and height be "h".
Now if we are holding a book at a certain height (h), <em><u>the potential energy will be maximum which is equal to mass× acceleration due to gravity× height (= mgh)</u>.</em>
(Remember: kinetic energy =0)
Now we consider that the book is dropped, in this case a force will act downward towards the centre of the earth, <em><u>Force= mass× acceleration due to gravity (F=mg)</u></em>. It is equal to the weight of the book.
While the book is falling, the potential energy stored in the book converts into kinetic energy and strikes the floor with <em><u>the maximum kinetic energy= (1/2)×mass×velocity² (=1/2mv²)</u>.</em>
(Remember: kinetic energy=0)
Due to this process the whole energy is conserved.
As the potential energy decreases kinetic energy increases.
Answer:
b.
Explanation:
In case of Single Slit, diffraction will occur.
Then In Single slit Diffraction, width of central fringe is
where D= distance b/w screen and slit
a= slit width
\lambda = wavelength
Thus if Screen width increases keeping other factors same then width of central fringe becomes narrower as
On increasing the slit width the central bright fringe width The width of the central bright fringe becomes narrower.
A :-) for this question , we should apply
F = ma
Given - F = 12 N
a = 0.20 m/s^2
Solution -
F = ma
12 = m x 0.20
m = 12 by 0.20
m = 60 kg
.:. The mass is 60 kg.
