Uploaded June 2021 | Updated September 2026, 3 weeks ago
Make new toys with your Dad!
Equipment: paper cups, bamboo skewers, wooden popsicle sticks, rubber bands, zip ties, plastic lids, bead, hot glue, scissors, pliers, wire cutters, awl, stationery knife.
Race car: Poke 4 holes in a paper cup. Cut 2 small pieces and 1 large piece from a paper straw, pass them through the holes in the cup, and fix in place with hot glue. Trim the straws to even their lengths and insert bamboo skewers as axles.
Make and enlarge holes in four bottle caps. Put the “wheels” on the axles. Make a hole in the bottom of the cup and thread a rubber band through it, fixing it to the base of the cup with a paperclip and to the rear axle with a zip tie. Put one more rubber band on each rear wheel. Spin the wheels back to start the engine. Your car is ready!
Helicopter: Poke 4 holes opposite each other in the bottom of a paper cup. Attach 4 wooden skewers to the end of a paper straw and cut off the excess part of the straw. Insert the construction into the holes in the cup and fix in place with hot glue.
Make a hole in the middle of a wooden popsicle stick. Unbend a paperclip and pass it through the hole in the stick, bend the end back, and attach to the popsicle stick with hot glue. Add a bead to your makeshift propeller and put it in place. Fold a large rubber band on itself and pass a bamboo skewer through it. Break the skewer to fit in the base of the paper cup and hot glue it in place. Bend the propeller shaft and put the rubber band on the hook. Cut “blades” from a second paper cup and hot glue them to the propeller. Start the helicopter by rotating the blades counterclockwise. Your helicopter is ready to fly!
Boat: Poke two holes in a paper cup and thread a straw through them, fixing it with hot glue. Break a wooden popsicle stick into 4 equal pieces. Make 4 “tabs'' opposite each other in a plastic bottle cap and hot glue a popsicle stick piece to each one. Repeat once more to make a second propeller. Open the “hull” of the boat. Cut off the excess of the straw on both the inside and outside of the boat and thread a skewer through. Fix a plastic tie in the middle of the axis and trim the tail. Make a hole in each bottle cap and put them on the axis. Make a hole in the front of the boat and thread a cut rubber band through it, tie a knot in the rubber band, and trim the excess. Glue a stern to the boat to keep water out. Put a candle in a glass and pour boiling water over it to melt it: the paraffin should float to the surface. Use this paraffin to coat the boat. Start the engine by hooking the rubber band to the zip tie. Place some ballast in the front of the boat and launch it into the water.
All three mechanisms are based on the law of conservation of energy: as it stretches, a rubber band stores potential energy. The rubber band lengthens as it is wound around the axle and twists with itself; elastic force then returns the rubber band to its original length. Potential energy is converted into kinetic energy: the rubber band spins the helicopter’s propeller, boat’s motor, and car’s axle.
Get even more cool toys with the MEL Kids subscription!
Warning! Only under adult supervision.
Make new toys with your Dad!
Equipment: paper cups, bamboo skewers, wooden popsicle sticks, rubber bands, zip ties, plastic lids, bead, hot glue, scissors, pliers, wire cutters, awl, stationery knife.
Race car: Poke 4 holes in a paper cup. Cut 2 small pieces and 1 large piece from a paper straw, pass them through the holes in the cup, and fix in place with hot glue. Trim the straws to even their lengths and insert bamboo skewers as axles.
Make and enlarge holes in four bottle caps. Put the “wheels” on the axles. Make a hole in the bottom of the cup and thread a rubber band through it, fixing it to the base of the cup with a paperclip and to the rear axle with a zip tie. Put one more rubber band on each rear wheel. Spin the wheels back to start the engine. Your car is ready!
Helicopter: Poke 4 holes opposite each other in the bottom of a paper cup. Attach 4 wooden skewers to the end of a paper straw and cut off the excess part of the straw. Insert the construction into the holes in the cup and fix in place with hot glue.
Make a hole in the middle of a wooden popsicle stick. Unbend a paperclip and pass it through the hole in the stick, bend the end back, and attach to the popsicle stick with hot glue. Add a bead to your makeshift propeller and put it in place. Fold a large rubber band on itself and pass a bamboo skewer through it. Break the skewer to fit in the base of the paper cup and hot glue it in place. Bend the propeller shaft and put the rubber band on the hook. Cut “blades” from a second paper cup and hot glue them to the propeller. Start the helicopter by rotating the blades counterclockwise. Your helicopter is ready to fly!
Boat: Poke two holes in a paper cup and thread a straw through them, fixing it with hot glue. Break a wooden popsicle stick into 4 equal pieces. Make 4 “tabs'' opposite each other in a plastic bottle cap and hot glue a popsicle stick piece to each one. Repeat once more to make a second propeller. Open the “hull” of the boat. Cut off the excess of the straw on both the inside and outside of the boat and thread a skewer through. Fix a plastic tie in the middle of the axis and trim the tail. Make a hole in each bottle cap and put them on the axis. Make a hole in the front of the boat and thread a cut rubber band through it, tie a knot in the rubber band, and trim the excess. Glue a stern to the boat to keep water out. Put a candle in a glass and pour boiling water over it to melt it: the paraffin should float to the surface. Use this paraffin to coat the boat. Start the engine by hooking the rubber band to the zip tie. Place some ballast in the front of the boat and launch it into the water.
All three mechanisms are based on the law of conservation of energy: as it stretches, a rubber band stores potential energy. The rubber band lengthens as it is wound around the axle and twists with itself; elastic force then returns the rubber band to its original length. Potential energy is converted into kinetic energy: the rubber band spins the helicopter’s propeller, boat’s motor, and car’s axle.
Get even more cool toys with the MEL Kids subscription!
Warning! Only under adult supervision.









![Explosive silver
Explosive silver in an explosive new video!
Reagents and equipment: calcium carbide, 50mL Tollens’ reagent, water, conical flasks, cork with gas pipe, funnel, filter paper, burner.
Add a small piece of calcium carbide to a conical flask with 50mL of water, and close it using a cork with a gas outlet tube. Immerse the free end of the gas outlet tube in 50mL of Tollens’ reagent. Wait for the reaction to die down. A loose, greyish-white precipitate will form in the second flask. Filter it through a funnel with filter paper and rinse with water. Pat the precipitate dry with filter paper and set a small amount on fire. And boom!
The reaction between calcium carbide and water produces acetylene gas and calcium hydroxide: CaC2+2H2O→Ca(OH)2+C2H2↑ Passing acetylene gas through a solution of Tollens’ reagent (ammonia silver hydroxide solution) yields a friable grey-white precipitate of silver acetylide: C2H2+2[Ag(NH3)2]OH→Ag2C2↓+4NH3↑+2H2O
Silver acetylide is an extremely unstable explosive. The fewer impurities it contains, the more dangerous it is. Silver acetylide can explode when heated and mechanically stressed.
Ag2C2(solid)→2Ag(solid)+2C(solid)
Safety precautions: Do not try this at home. Only under professional supervision. Explosive silver](https://i.ytimg.com/vi/EQmSTFGFdeo/mqdefault.jpg)
