Wind Racers.
Today, out group made some wind racers to figure out how wind resistance and force works. Our group made our wind racers look like toothless from the movie ‘how to train your dragon’. The martrial we used (not including the wooden trolley and the bamboo stick) were tape, black, green and white paint, cardboard, string, Popsicle sticks, and paper. Here were the steps we took to make the wind racers –
- First, draw the head of toothless on paper and cut it out.
- Next, tape (or make your friend) hold the cutout paper of toothless face onto a piece of cardboard and trace it.
- Then, once you finished tracing the face onto the cardboard, cut the cardboard face out then put it to the side.
- Next, grab a piece of A3 paper and trace out one of toothless wings.
- Cut of the paper of the wing and then trace it onto a big piece of cardboard.
- Once you finish tracing the one of the wings, flip the paper over so you can make the left side of the wing.
- Cut out both of the cardboard wings.
- Then, you paint the base layer of the face and wings black on both sides and wait for it to dry.
- Once the wings are finished drying of black paint, tilt the wings so its on a little bit on an angle and tape it onto the bamboo stick.
- Then put a skewer for reinforcement the wing and then tie a piece of string and tie it to the middle.
- Repeat the last step but do it on the other wing.
- Paint the face details onto the cardboard face. Make sure to paint the eyes green and white.
- Then once its finish drying, hot glue it on top of the tape so then it will stay confidently, but won’t stick onto the bamboo stick.
- Another optional step that our group did was to check out the wheels of the wooden trolley. We chose one with the smoothest types of wheels so then it will have less friction – making it easier to move forward.
There were four forces acting on my wind racer. Support, thrust, gravity and pull. They were unbalanced because when the leaf blower was pushing wind at the back, our wind racers were unstable because it went off to the side. It went unbalanced quickly because it accelerated, making it hard to go straight and therefore our wind racers fell on the ground. Net force is how we measure force when there is two given numbers either on the left and right side, or the top or the bottom. To figure out the net force, we subtract both the numbers and we measure it in N (Newtons). This means this could either be stationary (not moving), moving at a constant speed or accelerating. Our wind racer was unbalanced because when the wind blower blew, it leaned to the left and it fell over.
At the start of the journey, they had more of a thrust/push since the leaf blower was directly behind it. But as it got further from the leaf blower, the thrust force decreased and then the wind racers slowly got more friction, causing it to slow down and eventually stop. I think the reason why there was different results in the class was because some of them had too much weight on some side than the other and it caused a lot of them to fall down in the first five seconds. Or, some of them had a smaller area and things like newspaper and plastic bags to get as little air resistance as they can. After our group recorded our data, we had to calculate the speed. So we had to divide the distance by the time to figure out how fast our wind racers was truly going. It took 12.4 seconds to travel 7.3 meters. So we had to divide 12.4 by 7.3. The speed our wind racers went was 1.7ms-1.
Something that was successful was the wings, because when the leaf blower blew, the wings expanded, getting as much wind as they can. Something I could improve for the wind racers is to not use heavy materials but instead a lot of light materials and make it into like a sail. So it can trap most of the wind to help it accelerate forward.