A student sets up an experiment to investigate particle motion and heat transfer. He attaches a paperclip to an iron rod with wax. He suspends the iron rod above a spirit lamp and lights the spirit lamp to heat the rod. The setup is shown below. image A. The particles in the rod move towards the heat as the rod is heated by the spirit lamp. The movement of these particles causes the wax to become heated and melt, letting the paperclip fall to the table. B. The particles in the rod move away from the heat as the rod is heated by the spirit lamp. The movement of these particles causes the wax to become heated and melt, letting the paperclip fall to the table. C. The particles in the rod nearest to the spirit lamp begin to move faster when heated. These particles collide into nearby particles, slowly transferring heat energy along the rod to reach the wax. This causes the wax to melt, letting the paperclip fall to the table. D. The particles in the rod nearest to the spirit lamp begin to move slower when heated. These particles form a rigid grid with nearby particles, slowly transferring heat energy along the rod to reach the wax. This causes the wax to melt, letting the paperclip fall to the table.

the body's situation won't change the forces are equal opposit and on the same body

close lines strong magnet less close weaker

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.

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this