The cart experiences a frictional force which is directly proportional to its weight. This means that there must be a force applied on the car to balance the forces on the car to produce a net force of 0.
This is in accordance to Newton's first law which states that an object at rest will remain at rest and an object in motion will remain in motion unless an external force acts on it. The force must be a resultant force.
Therefore, the force needed increases with the total weight of the cart as well as with the added mass in a linear manner.
The IRB at the university will decide whether her study meets ethical guidelines before it is initiated. The importance of these codes of conduct is to safeguard research participants, the status of psychology and the researchers or psychologists themselves. Moral issues hardly yield a simple, unequivocal, right or wrong answer. It is consequently often a matter of judgment whether the research is justified or not. For instance, it might be that a study roots psychological or physical uneasiness to participants, maybe they agonize pain or maybe even come to solemn harm.
A. Fnet=ma
6*2=12N of force acting on the object in the direction it is accelerating
B. Fnet=ma
4*2=8N of force action on the object in the direction it is accelerating
