Sloan Gormley
A. Murray MacKay Bridge




For my parabola I choose the A. Murray MacKay Bridge. The A. Murray MacKay connecting Halifax and Dartmouth was built in 1970 when it became the first suspension bridge in North America to use orthotropic plate deck in its construction. After this work it is a bridge that can accommodate movements as high as 3.2 metres, which mean it is enabled to survive an earthquake. There is a large history around the site of this bridge, which is at the Narrows, a narrowing at the inner end of Halifax Harbor where it opens into the Bedford Basin. The Bedford Basin was where many fleets of ships were formed to carry troops and supplies to Europe during the First and Second World Wars. The Narrows was the site of the Halifax Explosion, where the French munitions ship Mont Blanc collided with another ship, drifted to the Halifax side of the Narrows, and exploded at 9:05 AM on December 6, 1917 completely destroying over 1600 homes and killing almost 2000 people in what was the largest man-made explosion in history before the atomic bomb was dropped on Hiroshima in 1945. A large area in the north end of the city was flattened in the blast and many thousands were left homeless.


Vertex: The vertex is (213,2) because half of the parabola, the middle of the bridge from pole to pole, is 213 meters, which is the x in (x,y) of the vertex. 2 is the y in the vertex because the lowest point in the vertex, the lowest y point of the parabola, or the bridge, is 2 meters away from the road, or the x axis, which by the way was my estimate I could not find the exact distance from the ground.


Equations: The equation for the parabola in...
Standard form: y=0.002x^2-0.852x+92.738
Vertex form: y-2=0.002(x-213)^2
Factored form: It cannot be put in factored form because the parabola has no x-intercepts.


Picture of Graph:
Screen_Shot_2012-05-28_at_9.12.14_PM.png


Y-Intercept: There is only one y-intercept for the parabola and that is the point (0,96).


Discriminant: The discriminant is -0.016


X-Intercept: There are no x-intercepts because the parabola never crosses or touches the x-axis.


Problem: A child is flying a kite on the A. Murray MacKay Bridge. The child is 2 meters tall, not including his kite. The kite, including the kite top and the string, is 25.5 meters. How long will the boy get before his flag touches the bridges parabola. The answer is 100 meters.