Thursday

July 31, 2014

July 31, 2014

Posted by **James** on Tuesday, August 23, 2011 at 5:22am.

above the ground.

The ball goes off the edge of the deck.

A model for the path of the ball once it leaves the deck is a parabola.

The equation of the parabola is y = ax^2+ bx + c.

The ball hits the ground at a horizontal distance of 3.1 m from the edge of the deck.

Find the values of a, b and c.

SHOW WORKING. STEP BY STEP

- math -
**drwls**, Tuesday, August 23, 2011 at 6:28amIf y is the height above the ground,

y = 5 when x = 0, so

a*0^2 + b*0 + c = 5,

so c = 5

When x = 0, the slope of the trajectory (path) is zero, so

dy/dx = 2ax + b = 0 at x = 0, so b = 0

When x = 3.1, y = 0, so

a(3.1)^2 +5 = 0

a = -5/(3.1)^2 = -0.521

y = -0.521 x^2 + 5

**Related Questions**

Physics - A ball is rolled off a table that is 0.481 m above the floor. The ball...

Physics - A small ball rolls horizontally off the edge of a tabletop of height h...

kvb - Sam hits a golf ball with a five-iron a distance of 120 m horizontally. A ...

Physics - Erica kicks a soccer ball 12 m/s at horizontally from the edge of the ...

Physics - A soccer player kicks a 0.43 kg ball straight up to see how far it ...

physics - player kicks football from ground level with velocity of32 m/s at an ...

Physics - A small ball rolls horizontally off the edge of a table that is 1.20 m...

physics - a ball rolls horizontally with a speed of 7.6 m/s off the edge of a ...

physics - A ball is thrown horizontally off the edge of a cliff with an initial ...

physics - A ball rolls horizontally with a speed of 7.6 m/s off the edge of a ...