Posts Tagged ‘range’

Cable transmission of signals

HS Varun asked:

How is it possible to transmit a no. of channels through the same cable ?
Is it based on the concept of Bandwidth ?

Answer:

In a cable TV system, each channel is assigned a range of frequency (6-8MHz range)

Radiations sensed by eyes

Arun Asked:
“What form of radiation can your eyes detect? sir, please answer this question”
Answer:
Normal Human Eyes can sense the visible spectrum only.

“The visible spectrum is the portion of the electromagnetic spectrum that is visibleto (can be detected by) the human eye. Electromagnetic radiation in this range ofwavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm.^[1] In terms of frequency, this corresponds to a band in the vicinity of 400–790 THz.” ———– Wikipedia

Kinematics Numerical

1. A particle travels 20 m in 7th second and 24m in 9th sec. find initial velocity?
2. in a projectile motion , a body thrown from the ground ,at what angle both the vertical height and range will be equal?
3. The velocity v(cm/s) of a particle is given in terms of time t(in seconds) by the equation v = at+b/t+c. Dimension of a,b, and c are ?

A Problem from Projectile motion

“A ball  is projected vertically  upwards  with  an initial  velocity of 28m/s and is observed  to pass a  point  30m above  the  projection point,at what  2times does  the ball  pass these  points?”

(Vimal Raj Answered)

ans : 1.356 sec and 1.444 sec .
sol:
from v=u+at we get t=2.8 . (time taken to reach the max height )
fm v²-u²=2aS we get S=39.2 m (max height reached)
observer at 30 m .
so , in btw distance btw observer and ball (at the top) =9.2 m
at top ball is at rest and time taken to reach the observer can be calculaed from S=ut + 1/2 at² ,we get t=1.356s .
and next time can be calculated by 2.8 – 1.356 =1.444 sec .

(The answer has not been scrutinized. If any error, teachers and visitors can post as comment)