If the 5,500 J of sound and light is the ONLY useful output
from the phone, then the phone's efficiency is
(5,500J / 10,000J) = 0.55 = 55% .
But the test engineer forgot one little minor almost insignificant detail.
As a test engineer myself, I'd say that he needs to turn in his laptop
and soldering iron, and think about changing his career to a job for
which he may be better suited, like 8 hours a day in a highway toll-booth.
What about that little radio transmitter and receiver inside the phone,
that maintain digital RF communication with the nearest cell tower ?
Without that microscopic radio transceiver ... plus 30 or 40 apps
that are always running unless you shut them off ... the device in your
pocket is essentially a flat rock with one side that sometimes glows.
ANSWER:
What is the difference between heat and light? - Physics Stack ... Heat and light are different but they are both forms of energy. Heat is a form of kinetic energy contained in the random motion of the particles of a material. Light is a form of electromagnetic energy. As with other forms of energy, heat energy can be transformed into light energy and vice versa.
The force must be applied for motor to keep the package moving is 50 N.
<h3>What is force?</h3>
Force is the action of push or pull the object in order to make it move or stop.
Power is related to force and velocity as
P = F x v
150 W = F x 3 m/s
F =50 N
Thus, the force must be applied for motor to keep the package moving is 50 N.
Learn more about force.
brainly.com/question/13191643
#SPJ1
Answer:
D. 130 J
Explanation:
The coefficient of performance for a machine that is being used to cool, is given by:
Here 
is the heat removed from the cold reservoir, W is the work required, that is, the energy required to remove the heat from the interior of the house, 
is the cold temperature and 
is the hot temperature. Recall use absolutes temperatures(
). Replacing and solving for W:
Answer: The machine must apply the force over a shorter distance. That's because a machine doesn't change the amount of work and work equals force times distance. Therefore, if force increases, distance must decrease
FALSE
HOPE THIS HELPS
