Answer:

Explanation:
since force is applied downwards at some angle with the horizontal
so here we will have

now we know that the box will not move if applied force is balanced by frictional force on it
so we will have




so here we can say





Answer:
" In the Balmer series, the transitions happening in visible range are considered, which range from around 400 nm to 700 nm. The longest wavelength visible in the Balmer series is 656 nm."
Explanation:
Hope this is helpful :)
Answer:
It should be A. Disturbance that travels through a medium or space, transmitting energy from one point to another.
I hope this helped you :)