Momentum and Impulse Lesson 1

Objectives Be able to define momentum and impulse, both qualitatively and quantitatively.

Momentum The only quantity of motion conserved in all collisions is mv. This makes it a very special quantity and is therefore afforded a special name … MOMENTUM. Direction is important for momentum and it is therefore a vector. Momentum is defined as the product of mass and velocity.

Scalar: Quantities with magnitude but no direction. Definition: Scalar: Quantities with magnitude but no direction. ( e.g. distance, speed, time and energy ) Vector: Quantities with magnitude and direction ( e.g. displacement, velocity, acceleration, force, momentum ) Computing With Momentum The quantity for an object is its momentum, given the symbol . Where p = momentum in kgm/s m = mass in kg v = velocity in m/s *

Example 1: What is the momentum of a 680 g toy train moving at 28 Example 1: What is the momentum of a 680 g toy train moving at 28.9 cm/s east? Example 2: If the momentum of a 0.374 kg softball is 5.89 kg·m/s W, what is its velocity? *

Example 3: If Glen’s momentum is 146 kg·m/s R at a speed of 3 Example 3: If Glen’s momentum is 146 kg·m/s R at a speed of 3.74 m/s, what is Glen’s mass? Example 4: If Tom’s mass with his bike is 61.4 kg and he speeds up from 4.17 m/s N to 9.49 m/s N, what is Tom’s change of momentum? *

Proportionalities and Momentum Example 1: If the mass of a moving object is doubled, what is its new momentum?

Example 2: If the speed of an obejct is reduced by a factor of 4, how has its momentum changed?

Newton’s 2nd Law and Momentum