Pre-Lab 4B: Acceleration

Purpose When you turn the track into a sloped ramp, the car can gain speed as it travels down the ramp. The speed of the car is constantly changing. What would a graph of this type of motion look like? Is there more than one way to graph the motion of an object? In this investigation you will learn what acceleration is, what the graphs associated with acceleration look like, and why they look the way they do.

Key Question What is acceleration?

Background define: Formula: Speed Formula: acceleration Definition: acceleration

Drawing

Procedure Section one: Attach the track to the 10th hole from the bottom of the Physics Stand. Place photogate A at position shown in photo. Keep photogate A in this position: do not move it!!

Section 2: sketch a position/time graph for a car down the ramp: place a predicted line of the car’s motion on it: flat, diagonal, curved? What is the title of this graph? Do a second predicted graph sketch for a speed/time graph What is the title for this graph?

Section 3: Move photogate B to different positions 10cm apart down the ramp Use the time through A to check the consistency of your release technique. If there is a very different time through A, re-do the trial.

Section four: Make a position/time graph (also known as what type of graph?)

Section 5: Move photogate B different positions 10cm down ramp Use the time through A to check the consistency of your release technique. If there is a very different time through A, re-do the trial. It is really important that you READ this section closely!!!! what is the distance used for this speed formula (table 2, column 5?) Draw a graph of speed/time (also known as what type of graph)

Section 6: a. Justify your answer means = use #’s Question B: Useing data from the trial in Table 2: where photogate B was: 70 cm from A Using the formula shown: SHOW YOUR WORK predict (show on the graph) how much time would elapse for the car to reach a speed of 150 cm/s on the speed vs time graph. NOTE: THIS IS A CHANGE FROM THE LAB WRITE UP: (do not use 200 cm/s)

Use your position vs. time graph to predict (show on the graph) where on the track the car would reach a speed of 150 cm/s (NOTE THE CHANGE) Now test your predictions and record each

Post Lab: 4B: acceleration

Key Question What is acceleration?

Background define: Formula: Speed Formula: acceleration Definition: acceleration

What does the speed graph look like: what are the axis labels? what happened to the distance traveled as the time goes by? How would you describe the data line (speed line)? How do you know the car does not travel at a constant speed?

What does the acceleration graph look like? what are the labels of the axis? What happens to the speed as the time increases? Describe the acceleration line, why does it look like this? Now draw an acceleration line of the car under a free fall.