Two particles are simultaneously thrown in horizontal direction from two points on a riverbank, which are at certain height above the water surface. The initial velocities of the particles are v1=5 m/s and v2=7.5 m/s respectively. Both particles fall into the water at the same time. First particle enters the water at a point s=10 m from the bank. Determine
a. the time of flight of the two particles,
b. the height from which they are thrown,
c. the point where the second particle falls in water.