A0.1-kg steel ball is dropped straight down onto a hard horizontal floor and bounces straight up. its speed just before and just after impact with the floor is 10 m/s. determine the magnitude of the impulse delivered to the floor by the steel ball. a) zero n • s b) 1 n • s c) 2 n • s d) 10 n • s e) 100 n • s

Impulse,

Explanation:

Given that,

Mass of the steel ball, m = 0.1 kg

Initial speed of the ball, u = -10 m/s (it straight down)

Final speed of the ball, v = +10 m/s (it straight up)

To find,

The magnitude of the impulse delivered to the floor by the steel ball.

Solution,

Let J is the magnitude of impulse. The change in momentum of an object to another is equal to the impulse delivered. Mathematically, it i given by :

J = 2 N.s

Therefore, the magnitude of the impulse delivered to the floor by the steel ball is 2 N.s. Hence, this is the required solution.

nah.   i'm just sleepy.

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.