- #1

vetgirl1990

- 85

- 3

## Homework Statement

A projectile is launched from an origin (0cm,0cm) on a tilted plane. The plane makes 30 degrees with the horizontal. The launcher sends the ball with a speed of 0.2m/s.

At what angle should the projectile be launched to hit the target at (0.7m,0.6m) location?

Assume there are no resistive forces to the projectile motion in this plane.

## Homework Equations

r_f = r_i + v_i*t + 1/2at

^{2}

Breaking the velocity vector into it's x and y components:

v_y = vsinΘ

v_x = vcosΘ

## The Attempt at a Solution

In the x-direction:

There is no acceleration in the x direction, so the above equation is reduced to:

x_f - x_i = vcosΘ*t

0.6 = vcosΘt

t = 0.3 / cosΘ (

**EQUATION 1)**

In the y-direction:

y_f - y_i = vsinΘt - 4.9t

^{2}

0.7 = vsinΘt - 4.9t

^{2}

**(EQUATION 2)**

SUB EQUATION 1 INTO 2

SUB EQUATION 1 INTO 2

0.7 = 0.2sinΘ (0.3/cosΘ) - 4.9(0.3/cosΘ)

^{2}

This is where I get stuck... solving the trigonometric equation. I can't find a solution, so I'm thinking that my above reasoning may be wrong.

Either that, or I am just having an incredibly hard time with trig -- which I've been out of practice for 8 years.

Any suggestions / guidance is very much appreciated.