Question

Projectile motion is a two dimensional motion with constant acceleration. Is this statement true or false?

Answer 1

Answer:

• Yes projectile motion is a 2D motion.
• But Constant acceleration is along y axis and acceleration is zero along x axis.

Hope it helps you

Answer 2

yes, of course, projectile motion is a two dimensional motion with constant acceleration.

let a particle projected with speed u at an angle θ with horizontal.

so, $u_x=ucos\theta$,$u_y=usin\theta$

in horizontal direction, there is no any acceleration acting on particle but in vertical direction particle experiences an acceleration i.e., g [ downward]

so, $a_x=0,a_y=-g$

velocity of particle after time t,

$v=ucos\theta t\hat{i}+(usin\theta-gt)\hat{j}$

and trajectory of particle is given as

$y=xtan\theta-\frac{gx^2}{2u^2cos^2\theta}$

here it is clear that particle moves in two dimensional motion and acceleration acting on it is constant and i.e., g [downward direction]