
i don't know what symbol ya'll use for wavelength so i just put the word instead.We use the greek symbol lambda.So just plug in everything you know.
wavelength=4.257×10^-7x10^-2 and
v=speed of light = 3×10^8
So you should get f= 7.04 ×10^15Hz
Explanation:
Draw a free body diagram of the toolbox. There are two forces:
Weight force mg pulling down,
and applied force F pulling up.
Sum of forces in the y direction:
∑F = ma
F − mg = ma
45 N − 15 N = (3 kg) a
a = 10 m/s²
The answer should be B. It's possible the answer key has a mistake.