Hands-on science (no lab required).After reading "Speed Skating speed skating Sport of racing on ice skates. The blade of the speed skate is longer and thinner than that of the hockey or figure skate. Two types of track are used in international competition. " (p. 18), try this activity to learn how stored energy converts to energy of motion. PREDICT Would a thicker or a thinner rubber band store more energy? MATERIALS 18 oz. empty oatmeal can * 1 sharpened sharp·en tr. & intr.v. sharp·ened, sharp·en·ing, sharp·ens To make or become sharp or sharper. sharp pencil * 2 size-33 rubber bands * 6 metal washers (quarter-size) * 2 cotton swabs "Q-Tip" redirects here. For the rapper, see Q-Tip (rapper). For the band, see Q-Tips (band). Cotton swabs (British English: cotton buds) are used in first aid, cosmetics application, and a variety of other uses. * cardboard Cardboard is a generic non-specific term for a heavy duty paper based product. Paperboard
Paperboard is a paper based material. It is often used for folding cartons, set-up boxes, carded packaging, etc. (28 cm by 38 cm, or 11 in. by 15 in.) * ruler * textbook textbook Informatics A treatise on a particular subject. See Bible. * tape * 2 size-64 rubber bands PROCEDURE 1 Use a sharpened pencil to carefully make a small hole in the center of the oatmeal container's lid and another in the center of the container's bottom. 2 Loop together two size-33 rubber bands (see illustrations, above). 3 Thread the looped rubber band through the center of 6 metal washers, and tie a knot knot In cording, the interlacement of parts of one or more ropes, cords, or other pliable materials, commonly used to bind objects together. Knots have existed from the time humans first used vines and cordlike fibers to bind stone heads to wood in primitive axes, and were tightly around the washers. (Make sure that the washers are in the center of the rubber band.) 4 Thread one end of the rubber band through the hole in the can's bottom. Then, slip a cotton swab through the rubber band loop poking through the hole. The swab will secure the band. 5 Thread the other end of the rubber the hole in the lid. Then, use another cotton swab to secure the loop poking through the hole. 6 Look inside the container to make sure that the rubber bands aren't twisted and that the washers aren't touching the container's sides. 7 Place a textbook flat on a smooth floor, giving yourself a cleared space of 2.5 m (8 ft). 8 Prop one end of a piece of cardboard (28 cm by 38 cm, or 11 in. by 15 in.) onto the book, with the other end on the floor. Tape the cardboard--your ramp--to the textbook. 9 Measure 18 cm (7 in.) up the ramp from the floor and draw a line across the cardboard. This line is the "roller's" starting point Noun 1. starting point - earliest limiting point terminus a quo commencement, get-go, offset, outset, showtime, starting time, beginning, start, kickoff, first - the time at which something is supposed to begin; "they got an early start"; "she knew from the . 10 Line up the edge of the "roller" with the line. Release the container down the ramp. 11 Place a piece of tape on the spot where the "roller" stops rolling forward rolling forward The liquidation of one option position by an investor at the same time that he or she takes an essentially identical position with a more distant maturity. . Let the container roll backwards and place a piece of tape where it stops again. 12 Measure the distance between the two pieces of tape and record the results. Remove the tape marks. 13 Look inside the container to make sure the rubber bands aren't twisted. Repeat Steps 10 to 12 two more times. 14 Take apart the roller. Then, repeat Steps 2 to 13 using two size-64 rubber bands. CONCLUSIONS 1 Why do you think the roller moved backward? 2 Which rubber bands--size 33 or size 64--sent the roller backward the farthest? Which had the greatest stored energy? 3 What else could you do to increase the roller's stored energy and energy of motion? ANSWERS 1. The "roller" rolls backward because of the following sequence: As the container moves forward, the rubber band untwists, Some of the stored energy gets converted into energy of motion. As the container continues to roll, the rubber band eventually twists again-turning some of the motion energy back into stored energy, When the container stops, the rubber band untwists, flipping Flipping Buying shares in an initial public offering (IPO), and then selling the shares immediately after the start of public trading to turn an immediate profit. flipping the washers and pushing the container backward. 2. Size-33 rubber bands should have given the "roller" the greatest stored energy. That's because they are more elastic elastic Of or relating to the demand for a good or service when the quantity purchased varies significantly in response to price changes in the good or service. than the size-64 bands. 3. Here are suggestions for ways to make the "roller" have more stored and motion energy: 1) Make the ramp steeper, That way, the container will start with more stored energy and roll farther. 2) Use smaller rubber bands to increase the tension. That should give the "roller" more stored energy, 3) Add more washers to the rubber band-but not too many or they will hit the container sides and produce the slowing force of friction. |
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