5. What is the change in momentum of a particle in uniform circular motion at diametrically opposite points?
Answers
Answer:
in moving from one point to another diametrically opposite point,(where momentum is P=mv) . 1-the magnitude of change in momentum is mv. 2-the mangnitude if change in momentum is 2mv
Answer:
If a particle is moving in a circle, it must have some acceleration acting towards the centre which is making it move around the centre. Since this acceleration is perpendicular to the velocity of a particle at every instant, it is only changing the direction of velocity and not magnitude and that’s why the motion is uniform circular motion. We call this acceleration centripetal acceleration (or radial acceleration), and the force acting towards the centre is called centripetal force.
In the case of uniform circular motion, the acceleration is:
ar = v2r = ω2r
If the mass of the particle is m, we can say from the second law of motion that:
F = ma
mv2r= mω2r
This is not a special force, actually force like tension or friction may be a cause of origination of centripetal force. When the vehicles turn on the roads, it is the frictional force between tyres and ground which provides the required centripetal force for turning.
So if a particle is moving in a uniform circular motion:
1) Its speed is constant
2) Velocity is changing at every instant
3) There is no tangential acceleration
4) Radial (centripetal) acceleration = ω2r
5) v=ωr
In case of non-uniform circular motion, there is some tangential acceleration due to which the speed of particle increases or decreases. The resultant acceleration is the vector sum of radial acceleration and tangential acceleration.
Uniform Circular Motion Examples
Following are the examples of uniform circular motion:
Motion of artificial satellites around the earth is an example of uniform circular motion. The gravitational force from the earth makes the satellites stay in the circular orbit around the earth.
The motion of electrons around its nucleus.
The motion of blades of the windmills.
The tip of second’s hand of a watch with circular dial shows uniform circular motion.
Frequently Asked Questions
What is the tendency to overturn by a cyclist if he turns around a curve at 15 miles/hour and if he doubles the speed?
From formula, we know that F=mv2r. This means that F∝v2. Therefore, it can be said that if v becomes double, then F will become four times. So the tendency to overturn is quadrupled.
Name the device used for measuring speed of rotation.
The tachometer is a device that is used for measuring the speed of rotation.
Explanation:
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