Sierra did 500 j of work to move her couch. if she exerts 250 n of force on the couch, how far did she move it? (work: w = fd)

0.5 m
2 m
250 m
750 m

2 m

Explanation:

The work done by Sierra is given by:

where

W is the work done

F is the force exerted on the couch

d is the distance through which the couch has been moved

In this problem, we know W=500 J and F=250 N; by re-arranging the equation, we can find the distance, d:

Answer : Distance = 2 m

Explanation :

Work done by Sierra, W = 500 J

Force exerted by Sierra, F = 250 N

We have to find the distance covered by the couch.

Using the definition of work done to find the distance.

Where

d is the distance covered by Sierra.

So, the distance covered by her is 2 m.

Hence, the correct option is (b) " 2 m ".

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.