A. I believe this might be the answer but
6 J/60 J= .1
.1 x 100= 10%
b. I'm not sure of this question
19. I'm not sure if I did this correct way or if there is a better way (I'm rusty)
300 J/.50 %= 600
600/100= 6 (answer)
20. (200 J)(.75%) = 150 (answer)
Check:
Efficiency: output/input x 100
150 J/200 J= .75
.75 x 100= 75%
Answer:
The correct option is (C).
Explanation:
Electric current can be direct or alternating.
The direct current flows only in one direction. It is unidirectional.
The alternating current or an C current reverse its direction periodically.
So, the correct statement regarding the alternating current is (c) i.e. Electrons reverse direction periodically.
Answer: force of gravity on the body due to height difference above the earth's surface
Explanation: as you increase the height of a body above ground, you do work against gravity in moving it from a point on the earth's surface to that point. So a body falling has a stored up gravito-potential energy which acts on it downward due to its mass, accelerating it downwards
Answer b): kinetic energy of the body
Explanation: the downward force produces an acceleration of magnitude 9.81m/s2 downwards which means an increasing velocity. This increasing velocity means the kinetic energy of the body is increasing (kinetic energy is proportional to velocity of the body squared)
Sunlight and gravity are not considered matter because sunlight does not have a rest mass that is characteristic of matter while gravity is just a vector component of matter.
<u>Explanation:</u>
Sunlight has energy and momentum that makes it similar to matter but it cannot be considered matter when you consider all the factors that are characteristic of matter. Light is an electromagnetic wave that is made up of photons and the protons do not have rest mass.
Gravity is a vector component of matter that has both magnitude as well as direction and the gravity increases with increase in mass of an object.
Answer:
Resistance = 400000 Ohms
Explanation:
Given the following data;
Voltage = 1200 V
Current = 3 mA = 3/1000 = 0.003 A
To find the resistance;
Voltage = current * resistance
Resistance = 1200/0.003
Resistance = 400000 Ohms
