## Electric Field at the centre of a half ring

A thin half-ring of radius R=20cm is uniformly charged with a total charge q=0.70nC.Find the magnitude of the electric field strength at the centre of this half-ring.

## Problem from Kinematics

the distance between Ahmadabad and vadodara is 100 km.two trains set off simultaneously from Ahmadabad towards vadodara each other.the speed of these trains are 45kmh-1 And 30kmh-1.when will they cross each other?

## A Few problems from Projectile Motion

1. If R and H are the horizontal range and maximum height attained by a projectile, than what is its speed of projection? please explain .

2. A particle projected from ground at angle 45 degrees with horizontal from distance ‘d1’ from the foot of a pole and just after touching the top of pole it falls on ground at a distance ‘d2’ from pole on other side, then what is the height of pole?please explain.

3. A particle projected from ground moves at angle 45 degrees with horizontal one second after projection and speed is minimum two seconds after the projection.What is the angle of projection of particle?(neglect the effect of air resistance) please explain.

4.A particle is moving on a circular path with constant speed v. It moves between two points A and B, which subtends an angle 60 degree at the centre of the circle. What are the magnitude of change in its velocity and change in magnitude of its velocity during motion from A to B respectively? please explain

Asked Shruti Suman Acharya

Answer

1.