A girl running a race accelerates at $2.5\, m s ^{-2}$ for the first $4\, s$ of the race. How far does she travel in this time ?
Given $u=0, a=2.5 m s ^{-2}, t=4 s$ and $S =?$
Substituting the values in equation
$S=u t+\frac{1}{2} a t^{2},$ we have
$S=0 \times 4+\frac{1}{2} \times 2.5 \times 4^{2}=20 m$
What does the slope of a displacement$-$time graph represent ? Can displacement$-$time sketch be parallel to the displacement axis ? Give reason to your answer.
By giving an example, prove that rest and motion are relative terms.
What is the nature of the displacement$-$time graph of a body moving with constant acceleration ?
Study the given graph and answer the following questions
$(i)$ Which part of the graph shows accelerated motion ?
$(ii)$ Which part of the graph shows retarded motion ?
$(iii)$ Calculate the distance travelled by the body in first $4$ seconds of journey graphically.
What conclusion can you draw from the displacement$-$time graph of a body shown below ?