Force, Mass, and Acceleration
It can be challenging to distinguish between the speed of an object and its acceleration. The “Forces and Motion: Basics” PhET can be used to measure both of these quantities and see how they relate to each other and to the applied force.
Directions

A- Open the “Acceleration” pane. Select the “Speed” box to show a speedometer and move the “Friction” slider to none.

B-Select the double, right arrow at intervals of a few seconds to increase the applied force by 50 N at a time until the character lets go. Observe what happens to the speedometer.

C- Reset the simulation. Again, display the speedometer and choose no friction. Replace the wooden crate with the refrigerator and repeat the experiment. Compare how much force is required for the refrigerator to reach the same speed as the crate. Do you think it takes a different amount of time to reach the same speed?

D-Repeat both experiments with the “Acceleration” box checked to display an acceleration meter. Observe how the acceleration meter relates to the applied force and to the speed of the object


Develop and Use Your Model

1-SEP Develop Models Draw one graph that shows how the speed changes as the force increases in 50 N increments and a second graph that shows how the acceleration changes under the same conditions.


2-SEP Conduct an Investigation Check the “Values” and “Masses” boxes and conduct experiments to demonstrate that, in the absence of friction, the acceleration is consistent with Newton’s second law of motion. See if you can determine whether the speed is changing at the same rate as the value of the acceleration that is displayed.