A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement-time graph is shown in Fig. Plot a velocity - time graph for the same.
For the initial $50\,\sec $, velocity is $2 \,m/s$. After that, velocity drops of zero ; as shown by vertical line in graph.
For the next $50\,\sec $, velocity is taken in negative because displacement is becoming zero.
A person is running along a circular path in a park.
$(a)$ At what point he changes his direction while running ?
$(b)$ If he covered half of the circular path, what will be his displacement ? Draw a diagram showing it.
Give an expression for the speed of an athlete if he takes time $'t^{\prime}$ to go around a circular track, of radius ${ }^{\prime} r^{\prime}$
What is meant by free fall ? Two bodies, one of mass $1\,g$ and other of mass $1\, kg$ are dropped from the same height in vacuum. Compare the two time intervals in which the two bodies will hit the ground.
If the average velocity of a body is equal to mean of its initial yelocity and final velocity, then the acceleration of the body is
Draw a velocity versus time graph for a body which starts to move with velocity $'u^{\prime}$ under a constant acceleration $'a'$ for time $t$. Using this graph derive an expression for distance covered $'S'$ in time $'t^{\prime}$