Centripetal Forces

While the bob is moving in the circular motion, the centripetal force that is provided is the spring. The spring causes the bob to get pulled inward and while it is being pulled inward while being rotated it provides a centripetal force. If this force was suddenly removed, the Bob would still have a centripetal force due to the rope in which it hangs from causing the inward force to keep moving in a circle. But if the forces are removed than its inertia would keep it moving in a straight line at constant speed. According to Newton's first law, is all force's were removed the bob would move with constant velocity, which could be zero, and zero acceleration. This is consistent with if the Bob had no forces acting upon it.

According to the equation F= m4Ñ€2R/T2, if everything remained constant while the mass increased, the centripetal force required to move in a circle motion would be higher due to the fact the mass increased. If the mass was doubled than the Force would be doubled as well due to the fact that mass is directly proportional to the centripetal force. Same thing applies if speed increases while everything else is constant, than the centripetal force increases as well, but not the same amount. By doubling the speed, the centripetal force increases by 4 times.

During the experiment when the masses were changed but the radii stayed the same, not only were the Bob's mass added to but also the hanging mass needed weight added to it to keep the centripetal force the same. For the .100 kilograms added to the mass of Bob, approximately .020 kilograms was added to the hanging mass, which made the hanging weight an increase of about .100 kilograms which is also the force of the spring for the radius. This is exactly what should have happened according to the predictions referring to the equation, F= m4Ñ€2R/T2, earlier.

When the radius was increased, not only was the force applied by the stretched spring increase, but also the velocity was increased. The radius was increased about 25%, which cause the velocity to be increased by almost 50%.