Data Entry - Physics

$A$ fireman of mass $60 \, kg$ slides down a pole. He is pressing the pole with a force of $600 \, N$. The coefficient of friction between the hands and the pole is $0.5$. With what acceleration will the fireman slide down (in $, m/s^2$)? (Take $g = 10 \, m/s^2$)

Identify the incorrect pair for Gymnosperms from the following:

$A$ series combination of resistor $(R)$ and capacitor $(C)$ is connected to an $A$.$C$. source of angular frequency $\omega$. Keeping the voltage same,if the frequency is changed to $\omega / 3$,the current becomes half of the original current. Then the ratio of the capacitive reactance and resistance at the former frequency is

Let $PQ$ and $RS$ be tangents at the extremities of the diameter $PR$ of a circle of radius $r$. If $PS$ and $RQ$ intersect at a point $X$ on the circumference of the circle,then $2r$ equals

The correct order of hydration enthalpies of alkali metal ions is