Collisions part a was very similar to a common type of question in physics, but I have never seen in any of the papers since 1997.
Anyone else use kinetic energy=potential energy, trig to find the height for E=mgh and then this again for the angle in iii?
10 b was unusual, to say the very least, while the last time that max range using calculus was asked in projectiles, it was answered so poorly that full marks were awarded just for getting to the equation to differentiate and saying "differentiate range with respect to angle"
Yes. First, u, a ands were the same. Time for first was x+2t, for second just x. Let displacement of particles equal each other, find an expression for time of second particle only (x), (excluding the 2t that was given in the question) and sub into the displacement formula for either of the particles, preferably the second one as it was so much simpler.