16. Suppose a person that has a mass of 60kg is standing on the ground. The force of friction between the person and the ground is a constant 300N. The person pushes horizontally against a truck with a force of 400N (the truck has mass 5000kg). The force of friction between the ground and the truck is also a constant 300N. a. What is the magnitude of the force that the truck exerts on the person?
b. Draw two free body diagrams. In one show the horizontal forces acting on the truck and in the other show the horizontal forces acting on the person. (use Newton’s third law to determine the force that the truck exerts on the person)
c. Determine the acceleration of the person using Newton’s second law and the forces acting on the person.
d. Determine the acceleration of the truck using Newton’s second law and the forces acting on it.
e. With these values for acceleration, how fast will the person and the truck be moving after half a second if both start from rest?

an enlarged virtual image

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.

= initial pressure

= final pressure = 2

= initial volume

= final volume = /4

= initial temperature = 20 c = 20 + 273 = 293 k

= final temperature = ?

using the equation