Plz help i dont understand A vehicle with a uniform velocity of 10ms^-1 is represented by which of the following graphs

B.

Explanation:

A position-time graph is a graph of the position of an object against (versus) time. The slope of the line of a position-time graph is typically used to determine or calculate the velocity of an object.  

Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.

Mathematically, velocity is given by the equation;

Uniform velocity can be defined as a situation in which a physical object or body travels equal distances in equal intervals of time along a fixed direction, regardless of how small the interval may be.

During uniform velocity, both the magnitude and direction of the physical object in motion do not change with respect to time. Also, an object in uniform velocity has zero tangential acceleration and its graph is a straight line parallel to the time axis.

Hence, a vehicle with a uniform velocity of 10 meters per seconds (m/s) is represented by Graph B.

the answer is b i think

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.