PHY 2020 Lecture Notes - Lecture 5: Pythagorean Theorem, Net Force, Headon
Document Summary
The kid pushes against the wall, the wall . Action :earth puling down on the rock. Figure 5. 14: forces are equal and opposite. Assume mass of rock= 1 kg: f=ma, 10 n=1 kg x 10 m/s ^2. Figure 5. 6- force is equal but opposite: damage isn(cid:495)t the same because mass isn(cid:495)t the same so little car gets the most damage. Checkpoint 2: two kinds of forces: internal + external. Same force is exerted on the cannon as the cannonball, just the masses- and therefore the accelerations are (cid:494)slightly(cid:495) different. Suppose that two carts, one twice as massive as the other, fly apart when the compressed spring the joins them is released. How fast does the heavier one roll compared to the small one: as fast. We represent vectors by -: the length represents the magnitude. Adding up vectors can be treated as a geometric problem: pythagorean theorem. Do not mix velocity vectors with force vectors.
