1D Kinematics Notes
- 2. • Distance vs. Displacement Distance the total path traveled. no direction (scalar) d=A+B+C+D+E C B D symbol for distance E x = resultant A R symbol for displacement (sometimes y) Displacement from the very beginning to the very end. includes direction so it is a vector
- 3. • Speed vs. Velocity Speed (v) distance divided by time (no direction, scalar) Velocity (v) displacement divided by time (vector) equation measured in x meters m v= = = t second s
- 4. Heather and Matt walk with an average velocity of 0.98 m/s eastward. If it takes them 34 min to walk to the store, what is their displacement? Step 1: Draw a picture. Step 2: Write out givens. Givens: v = 0.98 m/s 60 s t = 34 min x = 2040 s 1min Step 3: Convert units if necessary Step 4: Write out equation. x = v t Step 5: Substitute. x = (0.98)(2040) Step 6: Solve. x = 2000 m
- 5. • Some key points: • Remember: Velocity includes magnitude and direction • In one dimension, speed and velocity are calculated the same way.
- 6. • Acceleration change in velocity How fast you change how fast you’re going can change two ways: either change the symbol is “a” magnitude or the direction. unit is m/s2 Acceleration can be found as follows: a = vf– vi / t 5 total variables This equation says that Acceleration = final velocity – initial velocity x – displacement divided by time vi – initial velocity vf – final velocity http://www.physicsclassroom.com/mmedia/k inema/avd.cfm a – acceleration t – time
- 7. A sailboat starts from 0 m/s (rest) and accelerates at a rate of 0.21 m/s2 for 3 seconds. a. find the magnitude of the boat’s final velocity
- 8. • More key points: • Acceleration and velocity are NOT, NEVER HAVE BEEN, and NEVER WILL BE, the same thing. • http://www.physicsclassroom.com/mmedia/ki nema/acceln.cfm • Acceleration is the rate of CHANGE in velocity. • So, velocity is a rate; a change in distance over time. • Acceleration is a rate; a change in velocity • over time. Speeding up, slowing down, turning