What is the work function of the experimental photo-missive material? 0.50 ev -2.9 ev -1.2 ev -2.0 ev

The answer for this exercise is the last option, which is:

The explanation is shown below:

1. The graph shows the Photoelectric effect, which is defined as the ejection of electrons from a solid, this is caused by the incident of ligth. The maximum kinetic energy depends of the frequency of this ligth.

2. You must find the the graph shown in the figure attached to solve the exercise:

e) none of the above answers are correct

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be