Motion of a Dynamics Cart That Occur When Different Amounts of Net Force Are Applied on a System with Constant Mass

Objective:

In this laboratory activity, we will investigate the changes in the motion of a dynamics cart that occur when different amounts of net force are applied on a system with constant mass. And we will also investigate the changes in motion that occur when the applied force is constant, but the total mass of the system is changed.

Theory:

Newton's Second Law of Motion states that when a force acts on an object, it will cause the object to accelerate. The larger the mass of the object, the greater the force will need to be to cause it to accelerate. This Law may be written as force = mass x acceleration or:

F = m * a

Another way to state the Second Law is to say it takes more force to move a heavy object than it does to move a light object.

A cart is attached by a piece of string to another mass, which is hung over the table supporting the cart track by a pulley, so that as the hanging mass falls, it pulls the cart along the track.

Forces on Dynamics Cart with Hanging Mass

Equipment:

• Air track with glider

• Smart pulley

• Triple-Beam Balance

• Weights,

• String

• Timer

Procedure:

1. We placed the track on the laboratory table so that the pulley extends over the edge of the table. Level the track crosswise.

2. We placed the car on the far end of the track, away from the pulley; and adjust the slope of the track so that the car rolls at a constant speed toward the pulley, once started.

3. We adjusted the string and extended the end down to the floor. Hooked the weight hanger on the end of the string. We brought the car to the lower end of the track, so it touches the car capture. We cut off a section of string and attached the upper end to the car, so the weight hanger does not hit the floor.

4. With the glider pulled back away from the pulley, and with some mass on the end of the vertical string clip, we adjusted the height of the pulley so the string between it and the glider is parallel to the top crest of the air track and therefore horizontal.

5. We weighted the hanger, the car, and the bars.

6. We took a timer to measure the time when the car reaches.

7. We place a load of 500 g on the car. We used only the 50.0 g weight hanger. Moved the car near the upper end of the track so that the weight hanger was just below the pulley. Hold the car there. We took the timer; released the car and stopped the timer when the car hit the track.

8. For the second run, we placed one bar of 497.5 g on the card and the weight on the hanger remained the same, which were 50g. Repeated the step 7.

9.