It’s the crest, the crest is the top part of the wave and the trough is the bottom so they correspond
Work-Energy :W = 1/2 m ( Vf^2 -Vo^2 )
Vo = 24.0 m/s Initial speed
Vf = 27.5 m/s Final speed
W = 1/2 m ( Vf^2 -Vo^2 )
160 kj = 1/ 2 m ( 27.5^2 -24.0 ^2)
160kj = 4680 x m
convert kilo joules to jeoules 160000 j = 4689 xm
m = 160000 j/4689
m = 34.18 kg
I think your question should be:
An industrial laser is used to burn a hole through a piece of metal. The average intensity of the light is

What is the rms value of (a) the electric field and
(b) the magnetic field in the electromagnetic wave emitted by the laser
Answer:
a) 
b) 
Explanation:
To find the RMS value of the electric field, let's use the formula:

Where
;
;

Therefore
![E_r_m_s = sqrt*{(1.239*10^9W/m^2) / [(3.00*10^8m/s)*(8.85*10^-^1^2C^2/N.m^2)]}](https://tex.z-dn.net/?f=%20E_r_m_s%20%3D%20sqrt%2A%7B%281.239%2A10%5E9W%2Fm%5E2%29%20%2F%20%5B%283.00%2A10%5E8m%2Fs%29%2A%288.85%2A10%5E-%5E1%5E2C%5E2%2FN.m%5E2%29%5D%7D%20)

b) to find the magnetic field in the electromagnetic wave emitted by the laser we use:
;
;

Answer:
3 j
Explanation:
12.0 kilo / 4.00 meters = 3 j