November 28

The Physics of a Catapult

The catapult is an invention made by the ruler of Syracuse, Dionysius the Elder. It was made in 400 BC, it was a weapon for war. It was used in many wars until around the 14th century. Because when the 14th century came around they had invented gun powder and so they could make guns and cannons that could fire way faster and harder. The catapult became very quickly obsolete. However, Dionysius did make the mangonel there were other versions of this catapult. The Romans made a catapult called the ballista. The ballista was different because it was made like a giant crossbow. It would fire giant arrows and stakes. There was also the trebuchet made in 300 BC by the Chinese. A trebuchet uses a counter weight and gravity to fire the weapon while the other two use elastic force.

Day 1 : We drafted how we wanted the catapult to look and how we will make it.

Day 2: We changed our draft up a bit and started gathering necessary materials for the project

Day 3: We started to actually make the catapult. We ran into a slight calculation error. We hadn’t adjusted for the impact of the launch arm for when it hits the crossbar resulting in the crossbar breaking.

Day 4: We screwed in some pieces that were loose (like the crossbar). The screws really helped with the integrity of the catapult. We also test launched the catapult and it made good distance.

Our catapult worked with elastic forces. (you can see the red circle). We made the catapult out of wood and had a cylinder that would swivel to shoot the arm. To shoot the catapult we pulled back the arm(blue) and the elastics (red) would shoot it back up and when that would happen a projectile would shoot out of the basket(blue). A problem with the catapult is that the efficiency is not 100% because of the sound that it lets out and because it recoils and moves.

November 28

Week 12 in precalc 11

This week in precalc 11 we fiinished learning graphing linear and quadratic inequalities. The first thing you need to know is how to graph the line. If your equation says less than or greater than it will be a dotted line. If it is less than / greater than or equal to, you will have a solid line. Once you have drawn your dotted or solid line you have to figure out what side to shade. This is quite simple as ou just shade in the side that has the answers it is the same thing for parabolas.

This equation is y < x^2 + 2

November 28

Week 11 in precalc 11

This week in precalc 11 we started graphing and systems of equations I understand most of it so far although I will be missing the majority of the chapter because I will be away. We learned how this works with one and two variables this week. When you have one variable you can work on just the x axis but when you have two you can actually graph something. One thing I learned was figuring out if a point was a solution to an inequality. so if we have 2x – y<25 you have random coordinates like (6, -2)

then we’ll have something to solve and if the satement is true then it works. 2(6) – (-2) <25. 12 + 2 < 25. 14 < 25. So the statement is true becuse 14 is less than 25.