Mechanics 1: How do you calculate the magnitude of impulse exerted on a particle during a collision of two particles, given their masses and velocities.

Conservation of momentum is the key principle always used in problems of these type. Here, it asks for the impulse, which is a force measured in Newtons, and it is defined as the change in momentum. F=m(v-u). We apply this equation for just one of the particles, plug in its mass (m) and initial velocity (u) and final velocity (v), then take its modulus (positive value of the answer). On a side note, it is useful to know that if we were to calculate the impulse for the other particle involved in the collision, it would give us an equal and opposite answer (this may be used to check if our final answer is correct).