1 00:00:00,767 --> 00:00:15,382 [ MUSIC ] 2 00:00:15,382 --> 00:00:16,549 >> HELLO, EVERYONE. 3 00:00:16,549 --> 00:00:17,817 I'M ASTRONAUT RANDY BRESNIK, 4 00:00:17,817 --> 00:00:18,918 LIVING AND WORKING ABOARD 5 00:00:18,918 --> 00:00:21,154 THE INTERNATIONAL SPACE STATION. 6 00:00:21,154 --> 00:00:22,889 NOW, ON THE SPACE STATION, 7 00:00:22,889 --> 00:00:23,857 WE LIVE IN A MICROGRAVITY 8 00:00:23,857 --> 00:00:25,125 ENVIRONMENT. 9 00:00:25,125 --> 00:00:25,725 DO YOU THINK THE LAWS 10 00:00:25,725 --> 00:00:27,494 OF PHYSICS WILL HOLD UP? 11 00:00:27,494 --> 00:00:29,229 COME ON-- LET'S GO FIND OUT. 12 00:00:29,229 --> 00:00:32,599 [ MUSIC ] 13 00:00:32,599 --> 00:00:33,466 >> THE ACCELERATION OF 14 00:00:33,466 --> 00:00:34,434 AN OBJECT DEPENDS ON 15 00:00:34,434 --> 00:00:35,602 THE NET FORCE ACTING ON 16 00:00:35,602 --> 00:00:36,836 THE OBJECT AND THE MASS 17 00:00:36,836 --> 00:00:39,372 OF THE OBJECT, OR F = MA. 18 00:00:39,372 --> 00:00:41,174 >> JOLLY GOOD SHOW, SIR ISAAC! 19 00:00:41,174 --> 00:00:41,908 >> HERE WE SEE THAT 20 00:00:41,908 --> 00:00:42,942 ONCE THE FORCE OF THE THRUST 21 00:00:42,942 --> 00:00:43,910 IS GREATER THAN THE WEIGHT 22 00:00:43,910 --> 00:00:45,245 OF THE VEHICLE, THE ROCKET 23 00:00:45,245 --> 00:00:47,680 BEGINS TO ACCELERATE. 24 00:00:47,680 --> 00:00:48,448 >> I'M GOING TO START WITH 25 00:00:48,448 --> 00:00:50,049 SOMETHING SMALL, SOMETHING 26 00:00:50,049 --> 00:00:51,918 YOU MIGHT HAVE AT HOME-- 27 00:00:51,918 --> 00:00:54,988 A LITTLE STICK OF CHAPSTICK. 28 00:00:54,988 --> 00:00:55,755 WE'LL GO AHEAD AND USE 29 00:00:55,755 --> 00:00:56,990 OUR FORCE, BEING 30 00:00:56,990 --> 00:00:59,392 OUR BUNGEE CORD HERE. 31 00:00:59,392 --> 00:01:01,261 WE'LL PUT IT ON OUR BUNGEE 32 00:01:01,261 --> 00:01:02,862 AND WE'LL PULL IT BACK... 33 00:01:02,862 --> 00:01:04,531 AND LET IT GO. 34 00:01:04,531 --> 00:01:05,365 AND YOU CAN SEE HOW FAST 35 00:01:05,365 --> 00:01:06,699 IT ACCELERATES, BECAUSE 36 00:01:06,699 --> 00:01:09,102 THERE'S VERY LITTLE MASS. 37 00:01:09,102 --> 00:01:10,170 NEXT, WE'LL TRY 38 00:01:10,170 --> 00:01:12,372 A LITTLE SPACESHIP. 39 00:01:12,372 --> 00:01:13,873 A LITTLE MORE MASSIVE, AND 40 00:01:13,873 --> 00:01:15,108 YOU CAN FEEL THAT BECAUSE 41 00:01:15,108 --> 00:01:16,609 AS YOU MOVE IT, YOU CAN FEEL 42 00:01:16,609 --> 00:01:18,244 THE KIND OF EXTRA FORCE 43 00:01:18,244 --> 00:01:20,713 YOU HAVE TO PUSH WITH YOUR HAND. 44 00:01:20,713 --> 00:01:21,548 SO, WE'LL PUT OUR SPACESHIP 45 00:01:21,548 --> 00:01:24,017 ON OUR LAUNCHER HERE, 46 00:01:24,017 --> 00:01:28,421 SAME SPOT. 47 00:01:28,421 --> 00:01:29,122 NOTICE IT'S FLYING 48 00:01:29,122 --> 00:01:30,690 A LOT SLOWER THAN 49 00:01:30,690 --> 00:01:32,659 THAT CHAPSTICK DID. 50 00:01:32,659 --> 00:01:34,394 WHAT WE'VE SEEN IS THE SAME 51 00:01:34,394 --> 00:01:36,062 AMOUNT OF FORCE ON 52 00:01:36,062 --> 00:01:38,565 A SMALLER, LESS MASSIVE OBJECT 53 00:01:38,565 --> 00:01:40,333 MEANS IT ACCELERATES FASTER. 54 00:01:40,333 --> 00:01:41,100 WELL, THIS IS THE BIGGEST 55 00:01:41,100 --> 00:01:41,901 AND MOST MASSIVE THING 56 00:01:41,901 --> 00:01:43,470 WE HAVE, SO LET'S SEE HOW 57 00:01:43,470 --> 00:01:48,308 THE ACCELERATION IS AFFECTED. 58 00:01:48,308 --> 00:01:49,642 PULL BACK THE SAME AMOUNT 59 00:01:49,642 --> 00:01:53,146 ON THE FORCE, AND HERE WE GO. 60 00:01:57,517 --> 00:01:58,585 THERE YOU HAVE IT-- NEWTON'S 61 00:01:58,585 --> 00:02:02,422 2nd LAW OF MOTION IN ACTION. 62 00:02:02,422 --> 00:02:03,223 THANKS, EVERYBODY, FOR 63 00:02:03,223 --> 00:02:03,990 EXPLORING A LITTLE PHYSICS 64 00:02:03,990 --> 00:02:05,091 WITH ME TODAY. 65 00:02:05,091 --> 00:02:05,692 NOW, I'M GOING TO SEND IT 66 00:02:05,692 --> 00:02:06,726 BACK TO EARTH SO YOU CAN 67 00:02:06,726 --> 00:02:08,027 START YOUR EXPERIMENTS. 68 00:02:08,027 --> 00:02:09,462 SEE YOU AGAIN REAL SOON.