The lines represented by $ax^2 + 2hxy + by^2 = 0$ are perpendicular to each other,if ........

$A$ car is moving along a straight line,say $OP$ in the given figure. It moves from $O$ to $P$ in $18 \; s$ and returns from $P$ to $Q$ in $6.0 \; s$. What are the average velocity and average speed of the car in going from $O$ to $P$?

Identify $A$ and $B$ in the following reaction:
$C_2H_5Cl \xrightarrow{A} C_2H_5OH \xleftarrow{B} C_2H_5Cl$

There is an error of $\pm 0.04 \text{ cm}$ in the measurement of the diameter of a sphere. When the radius is $10 \text{ cm}$,the percentage error in the volume of the sphere is

$8 \ mol$ of $AB_{3(g)}$ are introduced into a $1.0 \ dm^3$ vessel. If it dissociates as $2AB_{3(g)} \rightleftharpoons A_{2(g)} + 3B_{2(g)}$. At equilibrium,$2 \ mol$ of $A_2$ are found to be present. The equilibrium constant of this reaction is

The solution of $\frac{dy}{dx} = \frac{y^2}{xy - x^2}$ is