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Definition: -This is the shape of the two-dimensional path followed by a projectile.

Example: This is seen in basketball shots, cannonball firings, and rocket launchings.

Hint: pa

Definition: -This is the shape of the two-dimensional path followed by a projectile-example-1

1 Answer

5 votes

Answer:

The shape of this path is known as a parabola.

Assumptions: there's no air resistance, and that gravitational pull is constant.

Step-by-step explanation:

The motion of a projectile can be considered in two separate directions:

  • In the vertical direction perpendicular to the ground, and
  • In the horizontal direction parallel to the ground.

In the vertical direction, the projectile would accelerating downwards at a constant rate. (That rate is equal to
g =\rm 9.81\;m\cdot s^(-2) near the surface of the earth.) If
v_(y,0) is the initial velocity of the projectile in the vertical direction, the height of the projectile at time
t would equal


\displaystyle y(t) = (1)/(2) g\cdot t^(2) + v_(y,0) \cdot t.

In the horizontal direction, the rocket travels at a constant speed. If
v_x is the initial horizontal velocity of the rocket, the horizontal position of the rocket at time
t would be


x(t) = v_x \cdot t.

Keep in mind that the two-dimensional path of the rocket is more like a function of height
y over horizontal position
x, rather than a function of height
y at time
t. The goal is to find
y(x), an expression of height
y in terms of horizontal position
x.

The relationship between
y and
t was already determined. Try expressing
t using
x with the help of the second equation.


x = v_x \cdot t.


\displaystyle t = (x)/(v_x).

Replace all occurances of the variable
t in the expression of
y using
\displaystyle (x)/(v_x).


\begin{aligned} y &= (1)/(2)\cdot \left((x)/(v_x)\right)^(2) + v_(y, 0) \cdot (x)/(v_x)\\&= (1)/(2v_x)\cdot x^(2) + (v_(y, 0))/(v_x)\cdot x\end{aligned}.

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