EPhys 11 (Physics for Engineers) Laboratory Exercise No. 1 Speed, Velocity and Acceleration Program Year & Section: _______________________________ Group No.: __________ Members: _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ Group/Member Rating: Criteria Rating Performance and Attitude Laboratory Safety Data, Results, and Computations Observation, Analysis and Conclusion Presentation of Report Total Score Date Submitted: _____________________________ 1 EPhys 11 (Physics for Engineers) Laboratory Exercise No. 1 Speed, Velocity and Acceleration Objective To demonstrate and determine the instantaneous and average velocity and acceleration of an object Method The setup enables the plunge to push the cart so that it moves away from the motion sensor, increasing its position relative to the motion sensor, until it collides with the end stop and returns, measuring the time and position, even the instantaneous velocity and acceleration of the cart. Apparatuses Pastrack (dynamic track) Smart Timer/Motion (Data collection system) Safety ● ● Pascar (dynamic cart) Motion Sensor/GLX/Sparklink/Airlink The cart carries speed and momentum, so be careful not to pinch fingers between the moving cart and the end stop when catching it. The plunger on the cart may release accidentally, so be careful not to hold the cart near anything breakable when the plunger is loaded. Procedure A. Instantaneous Velocity (Position 1) 1. Attach the motion sensor (one gate) near one end of the Pastrack (just after the starting position of the car) with the sensor’s sensing element pointing down the length of the track. Make certain that the switch on the top of the motion sensor is set to the cart icon. 2. Set the Smart Timer to SPEED (VELOCITY) and select one gate only. This will record the instantaneous speed (velocity) of the cart when it passes the gate. 3. Set the plunger of the Pascar in the desired amount of force (say at 2) and place the Pascar on the Pastrack with the plunger touching the end of the track. 4. Push the trigger of the plunger to release it and to start the cart moving. Careful not to touch the body of the cart to avoid impeding its motion. 5. Catch the cart at the other end of the Pastrack just after it hits the other end so as not to be sensed again by the sensor which can alter the measured value. 6. Record the value shown in the Smart Timer as instantaneous velocity in cm/s (Position 1) in Table 1.1. 7. Repeat Steps 2 to 6 twice to conduct three (3) trials. (Force applied should not vary in three trials) B. Instantaneous Velocity (Position 2) 8. Attach the motion sensor (one gate) near the other end of the Pastrack with the space between the sensor and the other end enough to allow the entire body of the Pascar to pass beyond the sensor. 9. Set the Smart Timer to SPEED (VELOCITY) and select one gate only. This will record the instantaneous speed (velocity) of the cart when it passes the gate. 10. Set the plunger of the Pascar in the desired amount of force (same with Procedure A) and place the Pascar on the Pastrack with the plunger touching the end of the track. 11. Push the trigger of the plunger to release it and to start the cart moving. Careful not to touch the body of the cart to avoid impeding its motion. 12. Catch the cart at the other end of the Pastrack just after it hits the other end so as not to be sensed again by the sensor which can alter the measured value. 13. Record the value shown in the Smart Timer as instantaneous velocity in cm/s (Position 2) in Table 1.1. 14. Repeat Steps 2 to 6 twice to conduct three (3) trials. (Force applied should not vary in three trials) 2 EPhys 11 (Physics for Engineers) C. Average Velocity 1. Attach the motion sensor (first gate) near one end of the Pastrack (Position 1) with the sensor’s sensing element pointing down the length of the track. Make certain that the switch on the top of the motion sensor is set to the cart icon. 2. Attach another motion sensor (this serves as the second gate) near the other end of the Pastrack (Position 2). 3. Measure the distance between the first and second gate in cm and record in Table 1.2 4. Set the Smart Timer to TIME and select two gates. This will record the time it takes for the cart to travel from the first gate to the second gate. 5. Set the plunger of the Pascar in the desired amount of force (same with Procedure A) and place the Pascar on the Pastrack with the plunger touching the end of the track. 6. Push the trigger of the plunger to release it and to start the cart moving. Careful not to touch the body of the cart to avoid impeding its motion. 7. 8. 9. 10. Catch the cart at the other end of the Pastrack just after the entire body passes the second gate. Record the time (in seconds) shown in Smart Timer in Table 1.2. Compute the average velocity of the cart. Repeat Steps 4 to 9 twice to conduct three (3) trials. (Force applied should not vary in three trials) D. Instantaneous Acceleration 1. Attach the motion sensor (first gate) near one end of the Pastrack (Position 1) with the sensor’s sensing element pointing down the length of the track. Make certain that the switch on the top of the motion sensor is set to the cart icon. 2. Set the Smart Timer to ACCELERATION and select one gate. This will record the instantaneous acceleration of the cart when it passes the first gate. 3. Set the plunger of the Pascar in the desired amount of force (same with Procedure A) and place the Pascar on the Pastrack with the plunger touching the end of the track. 4. Push the trigger of the plunger to release it and to start the cart moving. Careful not to touch the body of the cart to avoid impeding its motion. 5. Catch the cart at the other end of the Pastrack just after the entire body passes the second gate. 6. Record the value shown in Smart Timer in Table 1.3 as instantaneous acceleration (unit is cm/s2). 7. Repeat Steps 3 to 7 twice to conduct three (3) trials.(Force applied should not vary in three trials) E. Average Acceleration 1. Attach the motion sensor (first gate) near one end of the Pastrack (Position 1) with the sensor’s sensing element pointing down the length of the track. Make certain that the switch on the top of the motion sensor is set to the cart icon. 2. Attach another motion sensor (this serves as the second gate) near the other end of the Pastrack (Position 2). 3. Set the Smart Timer to ACCELERATION and select two gates. This will record the average acceleration of the cart when it moves from the first to the second gate. 3 EPhys 11 (Physics for Engineers) 4. 5. 6. 7. 8. 9. Set the plunger of the Pascar in the desired amount of force (same with Procedure A) and place the Pascar on the Pastrack with the plunger touching the end of the track. Push the trigger of the plunger to release it and to start the cart moving. Careful not to touch the body of the cart to avoid impeding its motion. Catch the cart at the other end of the Pastrack just after the entire body passes the second gate. Record the value shown in Smart Timer in Table 1.4 as average acceleration (unit is cm/s2). Repeat Steps 3 to 7 twice to conduct three (3) trials.(Force applied should not vary in three trials). Use extra sheets to show computations and to write the required observations, analysis/discussion and conclusions. Table 1.1 Instantaneous Velocity Instantaneous Velocity Position 1 Position 2 Trial 1 Trial 2 Trial 3 Average Value Table 1.2 Average Velocity Quantity Trial 1 Trial 2 Trial 3 Average Value Distance Time Average Velocity Table 1.3 Instantaneous Acceleration Measured Quantity Instantaneous Acceleration Average Value Average Acceleration Average Value Trial 1 Trial 2 Trial 3 Table 1.4 Average Acceleration Measured Quantity Trial 1 Trial 2 Trial 3 4
