C. Electromagnetic waves don't always need a medium to travel. Note that they do vary in wavelength and frequency however their speed is fixed. Also, EM waves are always transverse and they consist of vibrating electric and magnetic fields.
The tearing of paper is physical as it's still paper even when you tear it. A chemical reaction is when the substance is chemically change. ... When paper is burn, the cellulose in the air reacts with the oxygen to form carbon dioxide and water.
Therefore it's chemistry.
Answer:
A
Algebra For what values of the variables must ABCD be a parallelogram?
B
23. A 2y + 2 B 24. B
(3x + 10)
(8x + 5)º
3x + 6
54°
D
С
D
A
Зу - 9 с
ly+4
Answer:
Average speed, 
Explanation:
Given:
- Initial speed, u=40 cm/s
- final speed , v=20 cm/s
- Time taken, t=5 s
<u>First case</u>
Using equation of motion we have

Now using,

now putting the value of a in first equation we get

<u>Second case</u>
Acceleration
Time taken 
using equation of motion in one Dimension we have

Average speed is equal to total distance travelled per unit total time taken
