Changing Your Mind with Evidence

Question 1

Mia thinks a marble will roll down a steep ramp faster than down a gentle ramp. She builds two ramps of the same material, makes one steep and one gentle, and lets the marble start from the same spot on each. To her surprise, the marble reaches the bottom of the gentle ramp first. What is the best next step for Mia?

Accepted Answer

Think that her idea about steepness might be wrong, notice that the gentle ramp might be shorter, and plan a new test where both ramps are exactly the same length before deciding which is faster.

Answer

Say her original idea is still right and assume she accidentally gave the marble a bigger push on the gentle ramp.

Answer

Decide that marbles cannot roll on steep ramps at all and stop testing.

Answer

Believe the marble is magical and will always be faster on the gentle ramp, so she does not change anything.

Question 2

Ethan thinks that a helium balloon will rise higher if he adds a paperclip to it. He ties a balloon and puts one paperclip on the string; the balloon rises about 1 foot. Then he adds a second paperclip, but the balloon only rises a few inches. What should Ethan do with his original idea?

Accepted Answer

Realize that adding paperclips makes the balloon heavier and keeps it lower, so his original idea was wrong and should be changed.

Answer

Add even more paperclips because they must make the balloon go higher.

Answer

The balloon must have lost some helium, so he should use a new balloon.

Answer

The string might be tied too tightly; he should loosen the string and try again.

Question 3

You guessed that a small wooden block would sink when you put it in a bowl of water. When you try it, the block floats. What should you do?

Accepted Answer

Change your idea and say the block floats, because you saw it do that.

Answer

Keep saying the block will sink because that was your first guess.

Answer

Throw the block away and stop the experiment.

Answer

Ask a friend what they think the block will do next.

Try three questions

Ethan thinks that a helium balloon will rise higher if he adds a paperclip to it. He ties a balloon and puts one paperclip on the string; the balloon rises about 1 foot. Then he adds a second paperclip, but the balloon only rises a few inches. What should Ethan do with his original idea?

You guessed that a small wooden block would sink when you put it in a bowl of water. When you try it, the block floats. What should you do?

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