Question

This set of questions refer to a cart that can move forward and backwards along a horizontal line similar to the carts used in Lab. You may assume that friction is so small it can be ignored. For each of the motions described, select the appropriate shape of the graph of the applied force that would keep the cart moving as described. Away has been designated the positive direction. Each graph will have at least 1 label, however no more than1 label from each of the color coded groups. (.e. a minimum of 1, but no more than 3 labels per plot). Labels may be used on more than one graph.

the response in the photos has 2 out of the 18 boxes incorrect.

Answer 1

When the cart is moving away from the origin, with steadily decreasing velocity, the force on the cart should be constant and negative.

. If we consider to represent the given graphs as elements of a matrix (this is just for better understanding about which graph i am refering to, not any actual method), G(1,2) (the graph on 2nd row, 1st column) is the graph which represent this situation.

I will be using this notation from now on
If the cart moves with a constant velocity, the net force on the cart should be zero. so if time increases, the the force on the cart should remain zero. This is represented by graph G(1,1).

If the cart moves towards the origin with constant velocity, the force on the cart is zero, so the graph G(1,1).

If the cart moves towards the origin with steadily increasing velocity, then there is a constant negative force acting on the cart. this is shown by the graphs G(3,1). Here, we said that the force is positive, because the motion towards the -z axis is considered negative and since there is an increase in velocity, a change from , for example, -5 to -3 is considered positive, so the force should be positive.

When the cart is moving away from origin and if it speeds up and then slows down, we can understand that the force acting upon the cart was positive, and it became negative. So, there are two graphs which represent this. they are G(2,2) and G(3,2).

If the cart is pushed away and released, then there is no force acting on the cart after is has been released. So the total force on the cart will be zero after it is released, which is shown in G(1,1)

As far as i can tell, all the boxes are filled correctly.