DAY 48

#Goals: SWBAT...

1. Use scientific reasoning to answer impulse and momentum questions

2. Understand that a shorter time period (smaller delta t) results in a (larger/smaller) force

3. Use the impulse-momentum equation to solve momentum/impulse problems.

Warm-Up (5min):

HW check: chart, edpuzzle/notes. Warm-ups 39-48 later today during class

Recall: Impulse = F • t & Change in Momentum = m • ∆v

Impulse = Change in Momentum so.... F • t = m • ∆v

1. Momentum(1min): Is the momentum of a car traveling south different from that of the same car when it travels north at the same speed? Draw the momentum vectors to support your answer.
2. Momentum(1min): Which has more momentum, a supertanker tied to a dock or a falling raindrop?
3. Impulse and Momentum(3min): A 0.174-kg softball is pitched horizontally at 26.0 m/s. The ball moves in the opposite direction at 38.0 m/s after it is hit by the bat.
   1. Draw arrows showing the ball’s momentum before and after the bat hits it?
   2. What is the change in momentum of the ball?
   3. What is the impulse delivered by the bat?
   4. If the bat and softball are in contact for 0.80 ms, what is the average force that the bat exerts on the ball?

CLASSWORK

1. #048A: Relating Impulse and Momentum via a Virtual Egg Drop

• Answer the 14 questions in your notes (skip #6)
• Work in groups of two
• Activity is here: LINK
• If you're finishing the activity for HW, or were absent, the handout with questions is here: LINK

At Home Learning (HW)

1. if necessary, complete 048A

2. #048B: Take notes/answer edpuzzle questions here (2 videos):

(9:57) How to Wear a Helmet: a PSA from Flipping Physics - EDpuzzle

(3:58) Introduction to Conservation of Momentum with Demonstrations - EDpuzzle

Save for later

2. #048B:

We will solve example problem #1-1 together, and you'll do #1-2 and #2

1. A compact car, with mass 725 kg, is moving at 115 km/h toward the east. Sketch the moving car.
   1. Find the magnitude and direction of its momentum. Draw an arrow on your sketch showing the momentum.
   2. A second car, with a mass of 2175 kg, has the same momentum. What is its velocity?
2. The driver of the compact car in the previous problem suddenly applies the brakes hard for 2.0 s. As a result, an average force of 5.0103 N is exerted on the car to slow it down.
   1. What is the change in momentum; that is, the magnitude and direction of the impulse, on the car?
   2. Determine the momentum and the velocity of the car now.