Question #9243f

1 Answer
Sep 7, 2017

Consider it being thrown with an angle θ with the horizontal.

Then the velocity has two components ux=Ucosθ and uy=Usinθ.

The horizontal acceleration is ax=0 while that in vertical direction is ay=g

From an equation from kinematics,

y=uyt+12ayt2
y=Usinθt12gt2 is distance travelled by particle in y direction (vertical direction) in time t.

Also, x=uxt+12axt2
x=Ucosθt

Combining x and y,

y=xtanθ12gx2cos2θ

But for θ constant, tanθ=a and b=g2cos2θ,

We get,
y=ax+bx2

Which shows that the path is parabolic.

The equations of motion are,

Fx=max=0
Fy=may=mg

If however, the body is thrown vertically up, θ=π2

And thats when the x component of motion ceases the exist and, motion can be described as, by acceleration ay=g.

Then, y=Ut12gt2 describes the vertical distance travelled.