Answer:
The angle is 
Explanation:
From the question we are told that
The distance of the dartboard from the dart is 
The time taken is 
The horizontal component of the speed of the dart is mathematically represented as

where u is the the velocity at dart is lunched
so

substituting values

=> 
From projectile kinematics the time taken by the dart can be mathematically represented as

=> 


=> 
![\theta = tan^{-1} [0.277]](https://tex.z-dn.net/?f=%5Ctheta%20%20%3D%20%20tan%5E%7B-1%7D%20%5B0.277%5D)

Answer:
<u><em>Definition of spectral line: </em></u><em>one of a series of linear images formed by a spectrograph or similar instrument and corresponding to a narrow portion of the spectrum of the radiation emitted or absorbed by a particular source.</em>
<em />
<u><em>Definition of Wavelength:</em></u><em> can be defined as the distance between two successive crests or troughs of a wave. It is measured in the direction of the wave. ... Wavelength is inversely proportional to frequency. This means the longer the wavelength, lower the frequency.</em>
<em />
<em>So, the spectrum is the range of wavelength in visible light. While, wavelength is the length of a wave.</em>
<em></em>
Explanation:
I hope this helps!
When the heat source is removed from a fluid, convection currents in the fluid will eventually distribute heat uniformly throughout the fluid. When all of the fluid is at the same temperature, convection currents will stop.
States that particles are attracts with every other particle. wich force is directily proportional product of two masses and inversely proportional to the distance between the centers.