The posttion of an object moving along $x$ -axis ts given by $x=a+b t^{2}$ where $a=8.5\; \mathrm{m}, b=2.5 \;\mathrm{m} \mathrm{s}^{-2}$ and $t$ is measured in seconds. What is the average velocity between $t=2.0 \;\mathrm{s}$ and $t=4.0 \;\mathrm{s} ?$
$\text { Average veloctty } =\frac{x(4.0)-x(2.0)}{4.0-2.0}$
$=\frac{a+16 b-a-4 b}{2.0}=6.0 \times b$
$=6.0 \times 2.5=15 \mathrm{ms}^{-1}$
A car travels from $A$ to $ B $ at a speed of $20\,\,km/hr$ and returns at a speed of $30\,\,km/hr$. The average speed of the car for the whole journey is............$km/hr$
A man walks on a straight road from his home to a market $2.5\; km$ away with a speed of $5 \;km h ^{-1} .$ Finding the market closed, he instantly turns and walks back home with a speed of $7.5 \;km h ^{-1} .$ What is the magnitude of average velocity in $m/s$?
A car is moving along a straight line, say $OP$ in given figure. It moves from $O$ to $P$ in $18\; s$ and returns from $P$ to $\mathrm{Q}$ in $6.0\; s$. What are the average velocity and average speed of the car in going from $O$ to $P$?
''The magnitude of average velocity is equal to average speed''. This statement is not always correct and not always incorrect. Explain with example.
A particle is constrained to move on a straight line path. It returns to the starting point after $10\, sec$. The total distance covered by the particle during this time is $30\, m$. Which of the following statements about the motion of the particle is false