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Week 03 · Ball on Top

Monday

The ball on top challenge
// A tower that holds a ball up high
⏱ about 20 min

Monday: The Ball on Top Challenge

Rocket bounces a tennis ball across the lab floor.

"New challenge! Hold this ball up high," Rocket says.

Raven catches it. "How high is high? We need a number."

Nova projects a ruler in the air. "Would you like a hint? Five inches is a good number."

A goal you can measure

Up high is not a clear goal.

Five inches off the table is a clear goal.

You can check it with a ruler.

The challenge

  • Goal: hold a tennis ball at least 5 inches above the table.
  • The ball must stay up for ten seconds.
  • Use only 12 straws and tape.
  • Nobody may hold the tower.
CLEAR GOALS
  • Read the question.
  • Tap your answer.
Which goal can you check with a ruler?
The ball sits 6 inches up. Did it meet the goal?
The ball sits 3 inches up. Did it meet the goal?
RuleAllowed?
Use 12 straws and tape.?
Hold the tower with one finger.?
Use 20 straws.?
WHY THIS EXERCISEConstraints are part of the problem, so every build must follow them.
Draw two ways to hold the ball up.

Fuzzy goal or clear goal?

A fuzzy goal uses words like big, high or fast.

A clear goal uses a number.

Make it fast is fuzzy.

Roll it 3 feet in 5 seconds is clear.

FUZZY OR CLEAR?
  • Read the question.
  • Tap your answer.
Make a strong tower. Is that goal fuzzy or clear?
Hold the ball for ten seconds. Is that fuzzy or clear?
The ball sits exactly 5 inches up. Did it meet the goal?
Try it
Hold a ruler up next to a table leg.
Find the 5 inch mark.
Put a finger there. That is how high the ball must sit.
Safety first
Hold the ruler low and still.
Keep it away from faces.

You turned a fuzzy goal into a clear one!

Tomorrow, we meet a strong shape.