The centripetal force is supplied by a spring that is fastened between a rotatin

Question

The centripetal force is supplied by a spring that is fastened between a rotating rod and a suspended mass. For a given mass and radius of rotation, the speed of the mass can be determined by finding the time it requires to travel a set distance. The corresponding centripetal force can then be calculated by using equation 2. The centripetal force is equal to the magnitude of the static force produced by the spring in keeping the mass at a distance equal to the radius of rotation.

On the centripetal force apparatus, a movable indicator post is used as a reference point for the radius of rotation of the mass. The mass should always hang directly over the indicator post when the spring is detached and while the mass is not rotated. This assures that the string suspending the mass is perfectly vertical while doing the experiment. Attach the spring back onto the mass in order to do the experiment. The system can be rotated by applying a torque with the fingers to the knurled portion of the rotatable shaft. With a little practice, the rotation can be adjusted to keep the mass passing directly over the indicator. Be sure to adjust the counterbalance so that the rotation is smooth. To obtain v, measure the time required for at least 50 revolutions. This measurement should be done 5 times. Average all five measurements and calculate the centripetal force using MKS units.

1). Why is it important experimentally that when the mass is revolving at a uniform velocity we make our measurements with the mass hanging vertically?

2). If the mass was revolved at a greater velocity, the spring would be stretched a greater amount. How does this affect the force exerted by the spring on the mass?

Explanation / Answer

1) when we keep mass vertically then there won't be any effect of gravity on horizontally acting(towards radial) centripetal force so calculation becomes bit easy as for exact calculation you have to consider exact value of g as 9.81...

2)As we rotate faster our centripetal force increases to compensate that spring force F=-kx also increase to keep the net force zero in x direction( radial)

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.