PHYS 1003 Lecture Notes - Lecture 13: Elastic Collision, Kinetic Energy, Inelastic Collision
31 Oct 2016
School
Department
Course
Professor
Document Summary
They act to slow down any interaction between occupant and vehicle, which then in turn reduces the average force exerted. In a lot of situations, we have a flow of mass arriving onto a surface, colliding and transferring momentum. The force then depends on the mass flow per second , and the change in velocity on collision. But what must be noted is that the final answer is the force exerted by the roof to stop the rain. Therefore, by newton"s third law , the rain exerts a force of -2. 6 j n (downwards) on the roof. This was addressed in lecture 12, that if there is no external forces involved, linear momentum is conserved within the system (closed). Another example of the concept above (collisions with no external forces) is a rocket. A rocket works by the principle of conservation of momentum, because external forces are assumed to not be involved.
