Objectives

1. To explore the forces acting on a body that rests on Earth surface.
2. To explore unbalance forces.
3. To understand the effect of the forces of friction during the motion of objects.
4. To explore experimentally the Second Newton's Law (relation between force, mass and acceleration)

In your responses use scientific terms such as, constant, increase, decrease, velocity, force, mass and acceleration.

Click on the link below to open the simulation:

http://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-basics_en.html.

Part 1

You and some friends are at the park. You find some rope and decide you'd like to play a game of tug-of-war. Unfortunately, there are 5 people so you can't have an equal amount of people on each side. One of your friends suggests that the two biggest people should be on one side, while the three smaller people should be on the other side. Do you think this is a fair way to split up teams? Why or why not?

TASK 1

1. Place 2 people that are the same size the same distance away from the cart.
2. Make a prediction about the movement of the cart.
3. AFTER you have observed the actual movement, click on the sum of the forces box at the top right hand corner of the simulation. Record the number in the data chart.

	Predicted Movement	Actual Movement (none, left, right)	Sum of Forces (0, x-left, x-right)
Same size, same placement on rope.

O Sum of Forces Values Sound Reset All Left Force Right Force O