[scheduled:: 2025-01-27]
Lab 2 - Position and Speed of an Object
Links and useful resources
- START HERE: Physics 2024 class outline
- Handwritten math converter
- IXL science grade 8 (some physics skills)
- OpenSTAX high school physics
- NotebookLM physics notebook
- Physics projects
- Physics classroom online interactive tools
- AP Physics 1 Dan Fullerton videos
Lightning Round Questions
- What is the purpose of a pull-up or pull-down resistor? How does it work?
- What is the formula for the momentum of a moving mass?
- What is the formula for finding voltage drops in a two-resistor voltage divider?
- How much gravitational potential energy does a 10 kg mass have if it is 20 meters above the ground?
- gr7: [lightning:: 1]
- gr10: [lightning:: 3]
Lab procedure
Procedure
- Choose a starting place on the floor about 20 cm from the wall for your car with plenty of space ahead. Mark the starting point with a piece of tape approximately 10 cm long. Use the middle of this piece of tape as the starting line for your car.
- Starting from the point you marked in Step 1, measure half of a meter (50 cm) and place another piece of tape parallel to the first. Repeat this three more times so you have pieces of tape at 50 cm, 100 cm, 150 cm, and 200 cm from the starting line. See Figure 2.1. Make all measurements from the middle of the pieces of tape.
- Wind up the car and hold it in place at the starting line. Keep track of how much you wound the car so you can wind it the same amount in all trials.
- Countdown “3, 2, 1, go!” On go, one partner should release the car.
- The other partner should start the stopwatch when the front of the car crosses the first piece of tape. When the front of the car crosses the last piece of tape at 2.0 meters, stop the stopwatch. Record in Table 2.1 the amount of time it took for the car to travel 2.0 meters.
- Repeat Steps 3–5 two more times and record the measured times in Table 2.1.
- Using the measured distances and times, calculate the speed of the car for each trial and record the value in the last column of Table 2.1
Concept summary and connections
- average speed
- displacement vs distance
- instantaneous speed
- Computing speed from distance and time
Media resources
- Youtube search for "average speed"
- Youtube search for "displacement vs distance"
- Youtube search for "instantaneous speed"
- Youtube search for "Computing speed from distance and time"
Guided practice
- A student using a stopwatch finds that it takes his dog 15 s to run across his yard, which is 30 m wide. TEKS (4)(B)
- a. What is the dog’s average speed?
- b. Assuming that the dog is running at the same speed, how long would it take the dog to run across an 80-m wide yard?
- A student times a car traveling a distance of 2 m. She finds that it takes the car 5 s to travel the first meter and then another 8 s to travel the second meter. Is the car traveling at a constant speed? How do you know? TEKS (4)(B)
- Speed is defined as distance divided by time. In this lab, the unit of distance was meters and the unit of time was seconds. Therefore, the unit of speed was meters per second. Is miles per hour also a unit of speed? What about centimeters per minute? Why or why not?
Homework
- Devise a way to measure how fast water is moving in a river. What are some complications you will face?
- You drop a pinecone from one side of a 12-meter wide bridge into the stream below. in 5 seconds, it comes out the other side. How fast is the stream flowing?
- If you're in a car going 37 meters per second, how long will it take you to drive 100 miles?
- What are the components of a vector at angle 30 degrees with magnitude 8?
- Draw a motion diagram to represent a projectile launched from a catapult, from the moment it leaves the catapult to the moment it touches the ground.