The distance-time graph of an object is a straight line parallel to the time axis, then the object is _____.

The distance-time graph of a body is as shown in the figure. The part of the graph that represents the uniform speed of the body is

The distance-time graph of a moving vehicle is as shown in the figure.

A person starts from a point P and travels along a path PQRP as shown in the figure. Then speed of the person is _____ $\mathrm{m} {\mathrm{s}}^{-1}$.

A simple pendulum was given to a physics student to determine its time period. Arrange the following steps in sequential order to determine its time period.
(A) Calculate the radius of the bob 'R' by dividing the diameter by $2$.
(B) Take a metre scale and measure the length of the string from the point of suspension to the lower tip of the bob $\left(l_1\right)$.

(C) Place the bob over a metre scale and hold it in position with two wooden blocks or stiff cardboards. Measure the diameter $\left(D\right)$ of the bob.
(D) Now, the length of the pendulum$\left(l\right)$  is given by $\left(l_1-R\right)$.
(E) Consider the formula $T=2\pi \sqrt{\frac{l}{g}}$ Calculate the time period of the simple pendulum.