Answer:
1.The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
Answer:
a.2.5x 10^3 m/s
b.mr=48kg/s
Explanation:
A rocket is moving away from the solar system at a speed of 7.5 ✕ 103 m/s. It fires its engine, which ejects exhaust with a speed of 5.0 ✕ 103 m/s relative to the rocket. The mass of the rocket at this time is 6.0 ✕ 104 kg, and its acceleration is 4.0 m/s2. What is the velocity of the exhaust relative to the solar system? (B) At what rate was the exhaust ejected during the firing?
velocity of the exhaust relative to the solar system
velocity of the rocket -velocity of the exhaust relative to the rocket.
7.5 ✕ 103 m/s-5.0 ✕ 103 m/s
2.5x 10^3 m/s
. b we will look for the thrust of the rocket
T=ma
T=6.0 ✕ 104 kg*4.0 m/s2
T=2.4*10^5N
f=mass rate *velocity of the exhaust
T=2.4*10^5N=mr*5.0 ✕ 10^3 m/s
mr=2.4*10^5N/5.0 ✕ 10^3
mr=48kg/s
Answer:
If we put pressure on a solid or a liquid, there is essentially no change in volume. ... The kinetic-molecular theory explains why gases are more compressible than either liquids or solids. Gases are compressible because most of the volume of a gas is composed of the large amounts of empty space between the gas particles.
Explanation:
Answer:
Option C
Explanation:
Adiabatic cooling systems function similarly to dry cooling systems, but with the incorporation of pre-cooling pads; running water over pre-cooling pads and drawing air through the pads depresses the ambient dry bulb of the incoming air. The depressed dry bulb allows for greater system heat rejection.
he result of this is that adiabatic systems are highly effective in hot, dry environments, while using less water than traditional evaporative units. Adiabatic units also deliver the required cooling capacity in a smaller footprint and/or lower fan motor horsepower than a completely dry cooler/condenser.
