Sure, I don't take Chemistry so I can't describe that, but I take the other two subjects.
In the first year we learn some stuff like this:
-Nuclear particles, waves and wave-particle duality, materials, and moving bodies (momentum, acceleration, etc) for Physics
-Integration, differentiation, binomial expansions, graphs, trignometric functions, line equations, logarithms for Mathematics
-2D vectors, acceleration, friction of slopes, and moments for Mechanics (an optional part of Mathematics, other options that can be taken instead are Statistics and Decision Mathematics, again I don't know anything about them)
In the second year we then learn some more:
-Magnetic and gravitational fields, nuclear reactions, and rotational mechanics (optional, can be replaced with astronomical or medical physics) for Physics
-Further integration and differentiation (eg: of trig. functions), 3D vectors, further binomial expansion (eg: expansions to a negative power), and partial fractions for Mathematics
-Centres of mass for uniform solid or wireframe 2d shapes, and work energy & power for moving bodies in Mechanics
Although we learn similar things in Mechanics and Physics at times, the questions are very different, with Physics aiming towards understanding and using numerical values. Mechanics on the other hand, is focussed on the mathematical modelling and can instead ask questions like "A ball of mass M is projected with velocity U vertically upwards under a downwards gravitational acceleration of G, show that the maximum height reached by the ball (H) is equal to (U^2)/(2G)" or "Explain a method of improving the realism in the mathematical model"