Question

Projectile motion

Basically we take the value of acceleration due to gravity as -ve (−g), when an object is thrown in the opposite direction of g. But in projectile motion the object first opposed the g and travels towards g. So there is need for both +ve and -ve value of g, Then why we are using -g in vertical component throughout to derive equations to describe the the projectile.

Answer 1

In projectile motion, we use a negative value for the vertical acceleration, g, because we define the upward direction as positive. This decision makes the derivation of equations to describe projectile motion consistent and simplifies the analysis.

Step-by-step explanation:

When analyzing projectile motion, it is important to set up a coordinate system. Typically, we define the positive vertical direction as upwards and the positive horizontal direction as the direction of the object's motion. By defining the upward direction as positive, we set the vertical acceleration, g, to be negative (opposite to the direction of motion). This makes it consistent throughout the derivation of equations to describe projectile motion. It simplifies the equations and allows for a consistent treatment of the motion.