II. Net Force Table:
Directions for Set-Up
Before Pressing Go, which way do you think the cart will move? (None, Right, Left)
Why does the cart move that way?
What is the sum & direction of the forces?
(example: 70 Left)
Place 1 small blue guy on the very end of the left rope & 1 small red guy on the very end of the right rope
Place the medium blue guy on the very end of the left rope & 1 small red guy on the very end of the right rope
Place the big blue guy on the very end of the left rope & add all 4 of the red guys to the right rope
Before pressing Go, the cart will move to the right. This is because there is a greater net force acting on the cart in the right direction.
The cart moves to the right because the net force acting on it is greater in that direction. The net force is determined by adding up all the individual forces acting on the cart.
Initially, when only one small blue guy is placed on the left rope and one small red guy is placed on the right rope, the sum of the forces is 0. There is no net force acting on the cart, so it remains stationary.
When the medium blue guy is placed on the left rope and one small red guy is placed on the right rope, the sum of the forces is still 0. There is no net force, and the cart remains stationary.
Finally, when the big blue guy is placed on the left rope and all four red guys are added to the right rope, the sum of the forces is 70 to the right. The net force is now 70 to the right, which causes the cart to move in that direction.
Press Go and observe the motion of the cart.
Before pressing Go, I think the cart will move to the right.
The cart will move to the right because there is a greater net force acting towards the right side.
The sum and direction of the forces are 1 blue guy to the left and 2 red guys to the right (1:2).
Instructions for the second set-up:
Place the medium blue guy on the very end of the left rope and 1 small red guy on the very end of the right rope.
Press Go and observe the motion of the cart.
Before pressing Go, I think the cart will move to the right.
The cart will move to the right because there is still a greater net force acting towards the right side.
The sum and direction of the forces are 1 blue guy to the left and 1 red guy to the right (1:1).
Instructions for the third set-up:
Place the big blue guy on the very end of the left rope and add all 4 of the red guys to the right rope.
Press Go and observe the motion of the cart.
Before pressing Go, I think the cart will move to the left.
The cart will move to the left because the greater net force is now acting towards the left side. The combined force of the big blue guy is greater than the combined force of the 4 red guys.
The sum and direction of the forces are 1 blue guy to the left and 4 red guys to the right (1:4).
To determine the direction in which the cart will move, you need to analyze the net force acting on the cart.
1. Place one small blue guy on the very end of the left rope and one small red guy on the very end of the right rope.
Observe the forces acting on the cart. The small blue guy exerts a force to the left, and the small red guy exerts a force to the right. These forces are equal in magnitude and opposite in direction, resulting in a net force of zero. Therefore, the cart will not move in any direction.
2. Place the medium blue guy on the very end of the left rope and one small red guy on the very end of the right rope.
Again, analyze the forces. The medium blue guy exerts a force to the left, and the small red guy exerts a force to the right. However, the force from the medium blue guy is larger in magnitude compared to the small blue guy, resulting in a net force to the left. Therefore, the cart will move to the left.
3. Place the big blue guy on the very end of the left rope and add all four of the red guys to the right rope.
Examine the forces once again. The big blue guy exerts a force to the left, and the four red guys exert forces to the right. Since there are now four red guys, their combined force is greater in magnitude compared to the blue guy's force, resulting in a net force to the right. Therefore, the cart will move to the right.
In conclusion, the direction in which the cart will move depends on the relative magnitudes and directions of the forces exerted by the blue guys and the red guys.