Hello
The weight of the object is W=80 N and points downwards, in the vertical direction. The force F exerted by the forearm is perpendicular to the forearm itself, which is at an angle of
above the horizontal; therefore, the angle between the direction of the force F and the direction of the weight P is also
(but upwards). The component of the force F in the vertical direction is
and
must be equal to the weight of the object to compensate it. Therefore we can write
and from this we can find the intensity of the force F:
The answer is wavelength because The wavelength of visible light determines the color that the light appears. Light with the longest wavelength appears red, and light with the shortest wavelength appears violet. ... The wavelengths of visible light that an object reflects or transmits determine the color that the object appears to the human eye