Answer: Mechanical waves carry energy through a medium; electromagnetic waves carry energy through media and space.
Explanation:
<u>The waves which require medium to travel are known as mechanical waves. </u>The waves carry energy forward by compression and rarefaction that is by changing density /pressure of medium particles.
<u>Electromagnetic waves can transfer energy through space as well as medium. </u>In an electromagnetic wave, electric field generates magnetic field and magnetic field generates electric field. Electric field and magnetic field are perpendicular to each other and to the direction of motion.
Answer:
The principle of momentum conservation states that if there no external force the total momentum of the system before and after the collision is conserved.
Since momentum is a vector, we should investigate the directions and magnitudes of initial and final momentum.

If the first ball hits the second ball with an angle, we should separate the x- and y-components of the momentum (or velocity), and apply conservation of momentum separately on x- and y-directions.
This question sounds like it came after some activity where
some forces were observed. Since we were not there, and
we don't know what the activity was, we don't know what forces
were observed, and we have no clue to how they might be related
to the motion of the Earth around the sun.
P=w/t
w=15
t=3
therefore, 5 watts (b)
Tsunami and under water volcano