In a photoelectric experiment a parallel beam of monochromatic light with power of $$200$$ $$W$$ is incident on a perfectly absorbing cathode of work function $$6.25$$ $$ev.$$ The frequency of light is just above the threshold frequency so that the photoelectrons are emitted with negligible kinetic energy. Assume that the photoelectron emission efficiency is $$100\% $$. A potential difference of $$500$$ $$V$$ is applied between the cathode and the anode. All the emitted electrons are incident normally on the anode and are absorbed. The anode experiences a force $$F = n \times {10^{ - 4}}$$ $$N$$ due to the impact of the electrons. The value of $$n$$ is ______________. Mass of the electron $${M_e} = 9 \times {10^{ - 31}}\,kg$$ and $$1.0eV = 1.6 \times {10^{ - 19}}\,J.$$

A ball is projected from the ground at an angle of $${45^o}$$ with the horizontal surface. It reaches a maximum height of $$120$$ $$m$$ and returns to the ground. Upon hitting the ground for the first time, it loses half of its kinetic energy. Immediately after the bounce, the velocity of the ball makes an angle of $${30^o}$$ with the horizontal surface. The maximium height it reaches after the bounce, in metres, is ______________.