Answer :
Q.1 Calculate the different accelerations from the graph
At initial point (let O) the velocity was 0 m/s to reach point A when the velocity was 5 m/s it took nearly 3 seconds as we all know that acceleration is nothing but the change in velocity per unit time
[tex]a \: = \frac{dv}{t} [/tex]
[tex]a = \frac{5 - 0}{3} = \frac{5}{3} \: m/ {s}^{2} [/tex]
Similarly from point A to point B the acceleration was
[tex]a = \frac{dv}{t} = \frac{7 - 5}{3} = \frac{2}{3} m/s²[/tex]
From Point B to C the velocity was constant so the acceleration at that point would be zero.
in the same way we can calculate acceleration for rest other points.
Q.2 Explain why a Merry-Go-Round and a Ferris Wheel have a constant acceleration when they are moving?
We all know that Velocity is nothing but the speed with direction. Merry Go Round and a Ferris Wheel has constant speed but dynamic direction due to which the magnitude of velocity at every point differs with different sign hence it have a constant acceleration.