Afriend tosses a baseball out of his second floor window with initial velocity of 4.3m/s(42degrees below the horizontal). the ball starts from a height of 3.9m and you catch the ball 1.4m above the ground.
a) calc the time the ball is in the air (ans. 0.48s)
b)determine your horisontal distance from window (ans. 1.5 m)
c)calc the speed of ball as you catch it (ans: 8.2m/s)

i dont get what 42 m below the horizontal is, can someone give me direction on how to do this?

Part a)

Part b)

Part c)

Explanation:

As we know that the velocity of ball is

now the two components of velocity is given as

Part a)

now in Y direction we will have

so we have

Part b)

Now the distance covered by the ball in horizontal direction is given as

Part c)

speed in x direction will always remain the same

so we have

speed in y direction is given as

So final speed will be

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.