1). Systems at higher frequencies can carry more information
(data, pictures, channels, etc.) than at lower frequencies.
2). The "dish" antennas used for satellite communication, both on
the ground and on the satellite, have more gain at higher frequencies
than they have at lower ones.
3). Radio waves at frequencies lower than VHF reflect off of the
ionized layers of the atmosphere and return to Earth. They never
get out to where the satellites are.
4). All of the communication spectrum (frequencies) below VHF
were already being used for other services by the time satellite
communication started (in the 1960's).
Answer: 216.2 J
Explanation: The heat energy of copper is the expressed in Q=mc∆T. First make sure that the mass 0.0693 kg is converted into grams to cancel both units.
Q= 69.3 g x 390 J/g°C x 26 °C-18°C = 216.2J
Answer:
Explanation:
given,
speed of wind, = 14 m/s
frequency of horn,f_s = 1000 Hz
speed of sound,V = 344 m/s
frequency heard by the listener
using Doppler effect
f_L is the frequency of the sound heard by the listener
f_s is the frequency of sound emitted by the listener
V is the speed of sound
v_L is the speed of listener
v_s is the speed of source
now,
considering the frame of reference in which wind is at rest now, both listener and the source will be moving at 14 m/s
now on solving we will get
hence, the frequency heard by the listener is equal to 1000 Hz
osmosis and cellular transport - the physics of molecular movement, kinetic energy and diffusion.
Neither source is a renewable one.
