How do you obtain speed of a body from its distance time graph ?

What conclusion can you draw about the speed of a body from the following distance-time graph ?

How do you obtain a spectrum of light?

How do you obtain an alkene from alkyne?

How do you determine momentum of a body?

What can you say about the motion of a body if its speed-time graph is a straight line parallel to the time axis ?

How do you obtain pure sodium chloride from a crude sample?