The direction of acceleration of an object moving in a circular path is

$A$ train starting from rest picks up a speed of $10\, m s^{-1}$ in $100\, s$. It continues to move at the same speed for the next $250\, s$. It is then brought to rest in the next $50\, s$. Plot a speed-time graph for the entire motion of the train and calculate:
$(i)$ acceleration of the train while accelerating,
$(ii)$ retardation of the train while retarding,
$(iii)$ the total distance covered by the train.

Mention some uses of velocity-time graphs.

Ali,while driving to school,computes the average speed for his trip to be $20 \, km \, h^{-1}$. On his return trip along the same route,there is less traffic and the average speed is $30 \, km \, h^{-1}$. What is the average speed for Ali's entire trip?

What determines the direction of motion of an object: velocity or acceleration?

$(a)$ Define uniform circular motion.
$(b)$ Ram goes for a morning walk in a circular park daily. He completes one revolution of the park in $4$ minutes. Find his speed if the diameter of the park is $420\, m$.
$(c)$ Draw velocity$-$time graph for uniform motion along a straight line. How can you find the distance covered by a body from this graph?