Name __________________ Forces Go to http://phet.colorado.edu/simulations/sims.php?sim=Forces_in_1_Dimensionand click on Run Now.

Instructions1. Click on the slider to the left of the force graph and slide the bar up to a value of 1000 Newtons

(or as close as you can get). This is your APPLIED force. You may need to adjust the y values using the + and – buttons.

2. Press GO and watch the person push the file cabinet (mass = 200 kg) to the left. Press the PAUSE button before he hits the wall!!!!

3. Below sketch the TOTAL force-vs.-time graph below. (You can hide the friction force and applied force lines by clicking on the boxes to the left and down.) Only include the x and y axis and the shape of the line/curve.

4. Does the shape of the force-vs.-time graph make sense? Why?

Yes, this graph makes total sense; the total force is constant throughout the time interval. As a result the file cabinet accelerates.

5. Knowing the TOTAL force and the mass of the file cabinet, calculate its acceleration below. Hint: use Newton’s 2nd Law.

Using Newton’s 2nd law of motion,

So,

6. Hide the force-vs.-time graph by pressing on the X. Press on the GRAPH ACCELERATION button. Below sketch the acceleration-vs.-time graph. Again, only

include the x and y axis and the shape of the line/curve. Did the acceleration you calculated above in #5 match the acceleration value on the graph?

The value is exactly the same as calculated in last question.

7. Does the shape of the acceleration-vs.-time graph make sense? Why?

Yes, the graph makes sense, As force and mass are constant through whole interval so should be

acceleration and it is shown in graph and its value is 3.0 .

8. Hide the acceleration-vs.-time graph by pressing on the X. Press on the GRAPH VELOCITY button. Below sketch the velocity-vs.-time graph. Again, only include the x and y axis and the shape of the line/curve.

9. Does the shape of the velocity vs. time graph make sense? Why?

Yes, the graph of velocity makes sense. As acceleration is defined as rate of change of velocity and in previous question it is observed acceleration is constant which means slop of velocity should be constant. The graph gives the same representation for velocity i.e. a line with constant slop. The slop is positive which means velocity is increasing.

10. Hide the velocity-vs.-time graph by pressing on the X. Press on the GRAPH POSITION button. (Position is distance!) Below sketch the position-vs.-time graph. Again, only include the x and y axis and the shape of the line/curve.

11. Does the shape of the position vs. time graph make sense? Why?

Yes, the graph of position vs. time makes sense because two things are quite obvious from the graph i.e. the distance is increasing with time and as the velocity is increasing the slope for position vs. time also increasing which in other terms is speed of the object.

12. CLEAR the graph (left-hand button), hide the POSITION graph and reopen the APPLIED force graph.

13. Change the magnitude of the APPLIED force to about 1600 Newtons. You may need to adjust the y values by pressing on the + and – values. Again, press GO and watch the person push the file cabinet. Make sure to stop him before he hits the wall!!!

14. Knowing the new TOTAL force and the mass of the file cabinet, calculate its acceleration below.

So,

15. Hide the force-vs.-time graph by pressing on the X. Press on the GRAPH ACCELERATION button. Did the acceleration you calculated above in #5 match the acceleration value on the graph?

The graph for force-vs-time shows the value of acceleration 6.1 which is same as calculated

in last question rounded to 1 decimal place.

16. What happens to the acceleration of the file cabinet as you double the TOTAL force? Be specific!!!

The acceleration will be doubled as well.

17. What relationship exists between acceleration and force?

From our results acceleration is directly proportional to the applied force. The same fact is stated in Newton’s 2nd law of motion.

18. Select a lighter object to push. What do you notice about its acceleration?

Keeping the force same the acceleration is more for lighter object as compared to a heavier one. 19. What relationship exists between acceleration and the mass of an object?

It is observed that acceleration of an object is inversely proportional to its mass. More mass less acceleration and vice versa.