In a simple harmonic oscillator,at the mean position

The path of a projectile is given by the equation $y = ax - bx^2$,where $a$ and $b$ are constants and $x$ and $y$ are respectively horizontal and vertical distances of the projectile from the point of projection. The maximum height attained by the projectile and the angle of projection are respectively:

If a convex lens of focal length $80 \ cm$ and a concave lens of focal length $50 \ cm$ are combined together,what will be their resulting power?

Which one of the following statements is wrong?

During the electrolysis of copper sulphate aqueous solution using copper electrodes,the reaction taking place at the cathode is:

When radiation of wavelength $\lambda$ is incident on a metallic surface,the stopping potential is $4.8 \ V$. If the same surface is illuminated with radiation of double the wavelength,then the stopping potential becomes $1.6 \ V$. Then the threshold wavelength for the surface is