







Displacement 
20111217 

From faisal: a helicopter takes off and travels 300 km due north then returns to its landing field. what is its displacement? Answered by Penny Nom. 





A path around a pond 
20091031 

From adeniji: find the area of a concrete path 2m wide surrounding a circular pond 12m in diameter Answered by Penny Nom. 





The path of a baseball 
20080604 

From Tom: How high would a batter have to hit a ball to clear the stadium roof in right field
if the distance to the right field fence is 320 feet from home plate? Is this solvable? Answered by Janice Cotcher. 





The path of a submarine 
20060226 

From Meadow: Suppose that a submarine has been ordered to follow a path that keeps it equidistant from a circular island of radius r and a straight line shoreline that is 2 units from the edge of the island. Derive an equation of the submarine path, assuming that the shoreline has equation x = p and that the center of the island is on the xaxis. Answered by Penny Nom. 





The Terror Run 
20000318 

From Danny Mclean: A fairground's most popular attraction is a roller coaster ride known as the Terror Run. One stretch of track is called the Missile Path and is in the form of a parabolic curve. B is 180m horizontally from A and the highest point of the curve is 100m above A and B. A.. The owner works out a quadratic expression to describe the Missile Path. What is the expression He found? B.. A safety Engineer examined the structure and observed that points A and B were likely to be damaged due to the steepness of the Missile path near these points. The owner can see no way to make the Missile path less steep near A and B and to keep the height of the ride the same. HOW CAN IT BE DONE? Answered by Harley Weston. 





The twodigit numbers from 1099 
19980121 

From Alexis Riddle: My name is Alexis. I'm a student in 8th grade and I'm taking Algebra I Honors. My question is: In a string of numbers, two adjacent digits are considered as a twodigit number. For instance, the string 11012 contains the numbers 10, 11, and 12. What is the number of digits in the smallest string that contains all of the twodigit numbers from 1099? Please help and thank you for any assistance you can give me. Answered by Penny Nom. 

