Force and Acceleration Lab

Name ______

Objective: To observe the accelerations produced by varying forces on a given mass

Equipment: Lab cart pulley Metric masses paper clip Stop watch string Washers computer with Microsoft Excel

Procedure: 1. Load the cart with the following masses: 50 g, 100 g, and 200 g. Attach one end of a long string to the cart. Tie a paper clip to the other end of the string and pass it over the pulley. Hang metal washers on the clip until the friction force acting on the cart is just offset. Forces due to friction are offset when you can give the cart a very slight push and it moves at constant speed across the table. Do not remove the washers at any time. 2. Measure the distance that the mass will fall and record it below. Make sure your measurement is to 0.01 cm (2 decimal places). 3. Remove the 50 g mass from the cart and hang it on the end of the string. 4. Start the stop watch and release e the cart. Stop the stop watch and the cart when the 50 g mass reaches the floor. 5. Remove the 50 g mass from the string and put it back on the cart. Remove the 100 g mass from the cart and place it on the end of the string. Repeat step 4 for 100 g, 150 g, 200 g and 250 g by combining the masses. Be sure to place each mass back on the cart after using it. 6. Calculate the velocity of the cart for each trial and record in Table 1. 7. Calculate the average velocity for each mass and record in Table 2.

Distance mass falls ______cm

Table 1 Mass (g) Time (s) Velocity (cm/s) 50 50 50 100 100 100 150 150 150 200 200 200 250 250 250 Table 2 Mass 50 g 100 g 150 g 200 g 250 g Average Velocity (cm/s)

Interpretation

1. ON the same graph, make a velocity versus time plot for each mass. 2. The slope of a velocity-time graph is Δv/t which is the acceleration. Determine the slope of each of the lines on your velocity-time graph. Record each value in Table 3 next to the weight of the mass that accelerated the cart. 3. Plot a graph of acceleration (cm/s2) versus force with force on the horizontal axis. 4. Using your graph explain the relationship between force and acceleration.

5. Why does the mass remain constant even though you are removing mass from the cart during the trials?

6. Does it support Newton’s Second Law? Use evidence from your lab to support your answer.

7. Print your graphs and attach them to this page before turning in.

Table 3 Force (N) Acceleration (cm/s2) 0.05 0.10 0.15 0.20 0.25