I’m Martin Sullivan, I’m Director of the National Portrait Gallery, and thank you so much for coming and for contributing to this symposium, and we do hope that there will be a lively give and take. This is one of a series of symposia called the Edgar P. Richardson Symposia that were generously supported for […]

# Tag: Lecture

dear students, let us study law of conservation of momentum now as we have already studied in the previous chapter , about system of particles, for a system of particle we have studied that velocity of centre of mass , of a system of particle can be given by , total momentum of system divided […]

Our motivations are unbelievably interesting. I’ve been working on this for a few years and I find the topic still amazingly engaging and interesting, so I want to tell you about that. The science is really surprising. It’s a little bit freaky! We are not as endlessly manipulable and as predictable as you would think. […]

in this example we are given that a ball with a speed 9 meters per sec strikes, another identical ball at rest such that after collision, the direction of each ball makes an angle 30 degree with the original line of motion, and here we are required to find the speed of the two balls […]

On December 24, 1968, the astronauts of Apollo 8 were making their fourth orbit around the moon when they saw something that no other human being had seen before. As they began their rotation, the spacecraft windows caught the edge of the moon just as planet Earth appeared on the horizon. And for the first […]

let’s discuss about conservation of angular momentum in satellite motion. we know well that, in motion of a satellite, around a planet, we can say the only force acting on satellite is the gravitational force, only force on it, is gravity. and that too directed towards the center of the planet, we say only force […]

## 13. Physics | System of Particles | Solved Example-10 on Conservation of Momentum | Ashish Arora(GA)

this example says that a figure shows a spring block system , on which time varying force , 5 t is applied on two k g mass, and after ten sec velocity of three k g mass is observed to be thirty meters per sec, we are required to find velocity of two k g […]

in this example, we are given that a bullet of mass five k g is fired toward a twenty k g block at speed thirty meters per second , which is placed on smooth ground . it is observed that the bullet penetrates the block, and comes out at a speed of ten meters per […]

## 12. Class 11 Physics | System of Particles | Example-9 on Conservation of Momentum |Ashish Arora(GA)

in this example we are given, a triangular fixed wedge of height h, and angle of inclination theta , and is given that a block-a , which is also given is of mass m , is released from rest top of the a wedge block of height h, as shown in figure , if velocity […]

let us study a very important concept about, radio active beta emission, that is apparent violation of conservation laws in beta decay. it is observed that during beta decay, when it was discovered, the fundamental laws, are not being followed, or we can say when mathematically beta decay was analyzed based on experimental values, conservation […]