If a body dropped freely from a height of $20 ~m$ reaches the surface of a planet with a velocity of $31.4 ~ms^{-1}$,then the length of a simple pendulum that ticks seconds on the planet is (in $~m$)

Which of the products is formed when acetone is reacted with barium hydroxide solution?

In an experiment on photoelectric emission from a metallic surface,the wavelength of incident light is $2 \times 10^{-7} \ m$ and the stopping potential is $2.5 \ V$. The threshold frequency of the metal (in $Hz$) is approximately (charge of electron $e = 1.6 \times 10^{-19} \ C$,Planck's constant $h = 6.6 \times 10^{-34} \ J \cdot s$):

Which important greenhouse gas,other than methane,is produced from agricultural fields?

$A$ scion is grafted to a stock. The quality of fruits produced will be determined by the genotype of

If $1, \log_9(3^{1-x} + 2), \log_3(4 \cdot 3^x - 1)$ are in $A.P.$,then $x$ equals