Derive the equation $v^{2}-u^{2}=2 a S$ graphically.
Consider the figure given below
Now, area of trapezium $OABD$
$=\frac{( OA + BD ) \times OD }{2}$
Now, $OA =u, BD =v,$ and $OD =t$
Therefore, we have
$S =\frac{(u+v) t}{2}$
or $S=\frac{(u+v)(v-u)}{2 a},$ using $v=u+a t$
Hence, we have
$v^{2}-u^{2}=2 a S$
A car manufacturer advertises that the brakes are so perfect that the car stops instantaneously. Comment.
What kind of motion of a body is represented by the graphs given below ?
What can you conclude about the motion of a body depicted by the velocity-time graphs $(i), (ii)$ and $(iii)$ given below ?
The following graph describes the motion of a girl going to meet her friend who stays $50\, m$ from her house
$(i)$ How much time she takes to reach her friend's house ?
$(ii)$ What is the distance travelled by the girl during the time$-$interval $0$ to $12$ minute ?
$(iii)$ During which time-interval she is moving towards her house ?
$(iv)$ For how many minutes she was at rest, during the entire journey ?
$(v)$ Calculate the speed by which she returned home.
$(a)$ Differentiate acceleration from velocity.
$(b)$ Can a body have acceleration without change in magnitude of velocity ? Explain with an example.
$(c)$ A motor boat starting from rest on a lake accelerates in a straight line at a constant rate of $3\, m s ^{-2}$ for $8 \,s$. How far does the boat travel during this time ?