Power (rate of using energy) = (voltage) x (current)
Power of this heating element = (120 V) x (3.2 A) = 384 watts
The easy way:
384 watts = 0.384 kilowatt
(0.384 kilowatt) x (5 hours) = 1.92 kilowatt-hour
Another way:
384 watts = 384 joules per second .
(384 joule/sec) x (3600 sec/hour) x (5 hours)
= (384 x 3600 x 5) (joules) = 6,912,000 joules.
Answer:
Light travels as a wave. But unlike sound waves or water waves, it does not need any matter or material to carry its energy along. This means that light can travel through a vacuum—a completely airless space. (Sound, on the other hand, must travel through a solid, a liquid, or a gas.)
Explanation:
Answer:
1. Wave period = 0.962 s
2. Will absorb red and blue and reflect green
Explanation:
1.
The wave period is:

Wavelength is the distance between crests. So replacing the given information:

2. In simple words the color of an object is the light it reflects. A green object reflects green light, and the rest is absorbed (red and blue).
Answer:
40N
Explanation:
Since both weights are connected to one string, you can say that the tensions above each are equal to each other.
If you do the sum of forces for the 4kg mass, then the tension comes out to 40N (if we take gravity to be 10m/s²). But that seemed too good to be true, so I decided to do the work for the 7kg mass as well [which included finding the normal force (N) and plugging it into the sum of forces for the 7kg mass] to find that it also gives 40N as the answer.
If I were to put my process into steps:
- Write out the sum of Forces for both masses
- Set them equal to each other to find normal force (because this is the only unknown)
- Calculate and compare the two tensions to see if they are equal
*This all seems to line up perfectly, but do let me know if my answer doesn't match up with what you might find to he the answer later on.
Conduction is a mode of transfer of heat there