The maximum speed around a level curve is 30.0 km/h. what is the maximum speed around a curve with twice the radius?

When the radius is doubled, its speed will be 42.42 km/h.

Explanation:

Given that,

The maximum speed around a level curve is 30 km/h = 8.34 m/s

We need to find the maximum speed around a curve with twice the radius. The maximum speed of the object is given by :

............(1)

If radius is doubled, r' = 2r

The maximum speed is given by :

..........(2)

Dividing equation (1) and (2) we get :

v' = 42.42 km/h

So, when the radius is doubled, its speed will be 42.42 km/h. Hence, this is the required solution.

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.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.