The Magic School Bus Revving Up

Field Trip Notes
When The Magic School Bus's engine stops running, Mr. Junkett, a vehicle maintenance inspector, decides the bus should be junked. The class shrinks, dons fireproof suits and masks, and heads for the engine -- from the inside! There, they discover that the peanut-butter that Junkett accidentally dropped into the engine is blocking the fuel line, stopping air from mixing with gas, and keeping the spark plugs from sparking. While cleaning up the mess, the kids learn how an engine works. Can they get the Bus working again before Junkett has it pounded into a pancake?
The Great Balloon Race

Going Hands-On

Time: 40 minutes
Group size: Four

Since your students can't travel through The Magic School Bus's engine, to see what gets the wheels turning, they can explore another way to turn wheels: propulsion. Here, they'll see how the push from air-filled balloons turns the wheels of milk-carton 'buses.'

What You Need

  • 1 pint milk carton per group
  • Cardboard
  • Balloons (long, thin)
  • Straws
  • Scissors
  • Table
  • Masking tape
  • Rulers

Ahead of Time:
  • Punch four “axle” holes in the milk cartons. Holes should allow straws (axles) to turn easily.
  • Punch a fifth straw hole in the back of the carton.
  • Blow up balloons and let them deflate. Insert a straw one inch into the nick of each balloon. Secure the straw with tape or a rubber band.

Talk About It

Ask: What, besides a gas engine, can be used to move something on wheels?

What To Do
  1. Distribute materials. Help kids cut holes in the middle of wheels. Demonstrate how to blow up a balloon through a straw
  2. After students have assembled buses, let them test “engines” on an uncarpeted floor. They can measure and record the distances buses travel. Ask: What’s causing the bus to move? (Air, forced out of the balloon, propels the balloon - which pushes the bus.) What else is moved by propulsion? (rockets, jets)
  3. Ask: What if you blew up the balloon more? Less? Why? Try it.
  4. Hold three rounds of THE GREAT BALLOON RACE!

Next Stop
Have students create a scrapbook of engines powered by gas and other power sources (alternative fuels, electricity, pedal power in bicycles).
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