Section 1: Momentum and Impulse

Intro Video: http://www.cleanvideosearch.com/media/action/yt/watch?videoId=D3T8aXRZEQA

Just a few Q’s What is your understanding of momentum? What factors cause an object to have momentum? If an object has momentum, what does that tell you about it?

Momentum: Momentum is like inertia in motion. Momentum = Mass x Velocity Or p = mv Problem: A 200kg snowball travels with a velocity of 2 m/s. Find its momentum: Question: Would momentum be a vector or scalar quantity and why?

Impact Force: Force to create a change in momentum

Balloon Toss Demo: Get a partner and fill one balloon. Referrals to those who throw them at each other. 

Impulse: Change in momentum Derivation: When objects are stopped slowly….. When objects are stopped quickly….. (Demo: Desk Jump)

Impulse is the change in momentum 1) Increasing the _______& ______ of the impact 2) Increasing the change in ___________. F·t = mVf - mVi

https://www.youtube.com/watch?v=ozAG8t8_4M4

Sample Problem 1: Impulse b) Force to stop in .1s Find the following for a .5kg baseball when colliding with a wall and coming to a stop from 10m/s. Impulse b) Force to stop in .1s

Sample Problem 2: Find the following for the .5kg ball: a) Change in momentum b) Impulse c) Find the force if the moment of impact was .5s

Compression of a golf ball

Turbines

Reduce the impact force, so don’t forget to wear your helmet!

Warm-up: Find the Impulse for Each Situation Warm-up: Find the Impulse for Each Situation. The mass of the car is 1000kg

Warm-up: A cannon fires a 250kg projectile at 30m/s Warm-up: A cannon fires a 250kg projectile at 30m/s. If the force exerted by the cannon is 3,000N, find the following: Find the initial momentum before firing: Find the final momentum when the velocity is 300m/s: Find the change in momentum (impulse): 4) Find the time the force is applied:

Warm up: A 2. 5 kg ball strikes a wall with a velocity of 7 Warm up: A 2.5 kg ball strikes a wall with a velocity of 7.5 m/s and bounces back with a velocity of 5 m/s. If ball is in contact with the wall for .25s, find the force on the ball.

Quiz (10 pts): The following graph shows the force vs time the impact of a bat hitting a .4 kg ball. Use this information to find the following: Change in momentum. Final velocity of ball if it is initially at rest.

Momentum Quiz: (4 points each) A car that has a mass of 2,000 kg is initially traveling at 20 m/s when it hits an oncoming truck traveling at 40 m/s. If the car rebounds backwards off of the truck with a speed of 10 m/s, find the following: Initial momentum of the car: b) Final momentum of the car: c) Impulse (change in momentum) of the car: d) Force of contact if the collision time is .0021 seconds.

Warm up: Find the total momentum before and after the collision.

Extreme Egg Drop Lab Objective: Drop 3 eggs from 300 feet that survive. Rules: No dimension can be larger than 30 inch, max weight 5 lbs, no fluids or jells allowed, & max of 2 students per group. Grading: No eggs break- 30/30 1 egg breaks – 25/30 2 eggs break – 20/30 3 eggs break – 15 /30