An electromagnetic wave in a vacuum has a wavelength of 0.07 m. what is its frequency

The equation relating a wave's propagation speed to its frequency and wavelength:

v = fλ

v is the progatation speed, f is the frequency, and λ is the wavelength.

Given values:

For an EM wave in a vacuum, v = c ≈ 3×10⁸m/s

λ = 0.07m

Plug in the given values and solve for f:

3×10⁸ = 0.07×f

f = 4.3×10⁹Hz

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards