﻿[Script Info] Title: [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,0:00:00.00,0:00:03.00,Default,,0000,0000,0000,,If you happen to drive a car with a manual transmission Dialogue: 0,0:00:03.00,0:00:07.00,Default,,0000,0000,0000,,and you've ever let the battery die, well, there's a good chance you've had to push your car. Dialogue: 0,0:00:07.00,0:00:10.00,Default,,0000,0000,0000,,Let's talk about the forces involve in pushing a car. Dialogue: 0,0:00:10.00,0:00:12.00,Default,,0000,0000,0000,,Let's say we're lucky enough to have 3 people pushing this car. Dialogue: 0,0:00:12.00,0:00:17.00,Default,,0000,0000,0000,,Our green- and purple-haired doctors and, oh I don't know, Albert Einstein. Dialogue: 0,0:00:17.00,0:00:19.00,Default,,0000,0000,0000,,Let's say we're looking at this car from above. Dialogue: 0,0:00:19.00,0:00:23.00,Default,,0000,0000,0000,,Here's our bird's-eye view of the car--from above--and the mass of this car is 1000 kg. Dialogue: 0,0:00:23.00,0:00:28.00,Default,,0000,0000,0000,,Let's say Einstein is pushing from directly behind--here's the top of Einstein's head, Dialogue: 0,0:00:28.00,0:00:30.00,Default,,0000,0000,0000,,and there are his arms. Dialogue: 0,0:00:30.00,0:00:33.00,Default,,0000,0000,0000,,The green-haired doctor is pushing from the side at a small angle, you'll notice. Dialogue: 0,0:00:33.00,0:00:37.00,Default,,0000,0000,0000,,The purple-haired doctor is pushing from the other side, also at a small angle. Dialogue: 0,0:00:37.00,0:00:40.00,Default,,0000,0000,0000,,Let's say an interesting fact about this group of friends Dialogue: 0,0:00:40.00,0:00:43.00,Default,,0000,0000,0000,,is that they can all push with exactly the same force. Dialogue: 0,0:00:43.00,0:00:47.00,Default,,0000,0000,0000,,When they all push on this car at that same time with this exact same force, Dialogue: 0,0:00:47.00,0:00:51.00,Default,,0000,0000,0000,,the acceleration of the car is 0.5 m/s². Dialogue: 0,0:00:51.00,0:00:56.00,Default,,0000,0000,0000,,The angle that the green- and purple-haired doctors are pushing at we'll call α. Dialogue: 0,0:00:56.00,0:01:00.00,Default,,0000,0000,0000,,For this problem α is 30 degrees, so they're pushing at a 30-degree angle. Dialogue: 0,0:01:00.00,0:01:04.00,Default,,0000,0000,0000,,Einstein here is pushing directly up on the back of the car, Dialogue: 0,0:01:04.00,0:01:06.00,Default,,0000,0000,0000,,but these guys are doing it at a 30-degree angle. Dialogue: 0,0:01:06.00,0:01:10.00,Default,,0000,0000,0000,,I want you to tell me with what force is each person pushing. Dialogue: 0,0:01:10.00,9:59:59.99,Default,,0000,0000,0000,,Enter your answer here in Newtons.