Explanation:
Lasers produce a narrow beam of light in which all of the light waves have very similar wavelengths. The laser's light waves travel together with their peaks all lined up, or in phase. This is why laser beams are very narrow, very bright, and can be focused into a very tiny spot.
Answer:
Mass, m = 125 kg
Explanation:
Let us assume that the question says, "What is the mass of an object whose velocity is 400 m/s and the kinetic energy of 10⁷ J.
The kinetic energy of an object is :

So, the mass of the object is 125 kg.
A wooden log is displaced to a distance of 20m in 10 seconds by applying 500N effort . Calculate the workdone and power...
Solution,
displacement = 20 m
time = 10 sec
force = 500 N
work done = ?
power = ?
Now ,
work done = f × s
= 500 N × 20 m
= 10000 j
Now ,

~nightmare 5474~