University:
Arizona State University
Course:
PHYS 102 | Introductory Physics I
Academic year:

2024
Views:

380

Pages:

4
Author:

Mohammed N.

Ballistics Ballistics is the branch of mechanics concerned with the launching, flight behavior and impact effects of projectiles. Suppose you fire a bullet horizontally. We can break down the velocity of the projectile into a horizontal component (xV) and a vertical component (yV) and consider its motion as the superimposition of two independent motions: one along x-axis and the other along the y. The projectile leaves the barrel instantly t = 0 with an initial velocity v0 and from this moment on only the direct weight on the y-axis and no direct force on the x-axis acts on it. So at any moment t> 0: In the equation of the trajectory of the bullet, we can see that the curve obtained is an arc of parabola with vertex in O, and it is very easy to make a graphic construction Let's examine the most general case: the motion of a projectile with initial velocity vo forming an angle & on the horizontal direction. We divide the velocity into the two components and study the motion in the two directions The following trajectory equation geometrically represents a parabola The ordinate of A is the maximum height (h) reached by the projectile that can be calculated by observing yV which is cancelled in A and then reversed in sign. Friction Friction is a force exerted between two objects in contact. It opposes their movement. There are 3 types of friction: grazing, rolling and viscous. Dry friction is generated by the sliding of an objects on a surface without rolling. μ is called coefficient of friction (it is a value that depends on the materials and surfaces involved, has no unit of measurement) and is multiplied by the perpendicular component of F. The formula of rolling friction: Weight The weight is the force that a gravitational field exerts on an objects having mass. Weight is the gravitational interaction that acts between any two massed objects. The mass is measured in Kg, it is a scalar quantity and does not vary with the variation of its position in space. Weight is a force and is measured in Newton (N). g is the gravitational acceleration. This value on Earth is: