# Flash Cards

Magnetism

## Helical Path: Charges in Magnetic Field with Solved Example

The helical path is the path of the motion of a charged particle when enters at an angle of $\theta$ in a uniform magnetic field $B$. In this short tutorial, we explain the factors that cause this type of motion. On a moving charged particle in a uniform magnetic field, a magnetic force of magnitude $F_B=qvB\,\sin \theta$ is acted where $\theta$ is the angle of velocity vector $v$ with the magnetic field vector $B$. This is the main factor that creates a spiral or helical path.  A charged particle (say, electron) can enter a region filled with uniform $B$ either with right angle $\theta=90^\circ$ or at angle $\theta$. In the former case, its path results in a ci

kinematic

## Acceleration on Position-Time Graph

How to find acceleration from a position vs. time graph?  Answer: Acceleration on a position vs. time graph can be obtained, numerically by having the initial position and velocity of a moving object Or graphically, by observing the curvature of the $x-t$ graph. A graph, looking like an upside-down bowl, represents a negative acceleration and vice versa.  In this long article, we want to show you how to find constant acceleration from a position-time graph with some solved problems. You can skip this introduction and refer to the worked examples.    Types of Motion: An object can move at a constant speed or have a changing velocity. Suppose you a

kinematic

## Displacement and distance problems with solutions

Problems and Solutions about displacement and distance are presented which is helpful for high school and college students. In the following, displacement is computed for simple cases.   Displacement Problems: Problem (1): An object moves from point A to B, C, and D finally, along a rectangle.  (a) Find the magnitude and direction of the displacement vector of the object? (b) Find the distance traveled by that object? (c) Suppose the object returns to point A, its initial position. Now, Find the displacement and distance. Solution: (a) By definition of displacement, connect the initial (A) and final (D) points together. As shown, displace