Multiple Choice
Why is it hard to win a tug-of-war against a group of teachers?
a. Teachers try really hard.
b. Teachers have more legs than students.
c. Teachers have a lot of friction.
d. Teachers can push really hard.
1. Why do hoppers hop off the table?
Hoppers hop off of the table because of the rubber band
The rubber band is stretched when the hopper is flat. The stretched rubber band is pulling on the sides of the cardboard. When you let go, the rubber band contracts and pulls the sides together causing the cardboard to push off of the table. This push makes the hopper fly up in the air
2. The last rubber band caused the watermelon to burst because _________.
a. it was stronger than the other rubber bands.
b. it was thicker than the other rubber bands.
c. it was the last rubber band in the bag.
d. it created a force that was greater than the force of the watermelon rind.
2. Why are pillar bridges and arch bridges stronger than board bridges?
The force of people and cars pushes down on bridges. The pillars and arches push up from below to balance the downward push force from the people and cars. The board bridge does not have anything to provide the push from underneath.
3. Why was a suspension bridge a good design for the Golden Gate Bridge in San Francisco?
a. Ships had to pass underneath the bridge.
b. It has a lot of pillars underneath to support it.
c. The distance the bridge had to cross wasn’t very long.
d. The water under the bridge was very shallow.
Imagine a trapeze artist wants to make their trapeze swing more slowly. How should they do this? Should they have a second trapeze artist join them, so that there is more weight? Or should they make the ropes shorter or longer? On the lines below, explain how you know which change to make.
I think they should make the ropes longer. I think this because we tested different lengths of rope. When the ropes of our trapeze were longer, our trapeze swung more slowly. We also tried adding weight to the trapeze, and it didn’t change how fast the trapeze swung. So adding another trapeze artist won’t make it swing more slowly.
4. A trapeze won’t swing forever because ___________.
a. a trapeze is too heavy to keep swinging.
b. friction and air resistance slow the trapeze down.
c. a trapeze isn’t heavy enough to keep swinging.
d. the ropes of the trapeze aren’t long enough.
Are paper clips magnets? Explain
Paper clips are not magnets but they can become magnetized by coming in contact with magnets. The paper clips that are touching magnets can pick up other things made of iron and will stay magnetized for a short time after the magnet is removed.
5. Magnets attract _____________.
a. objects that contain iron.
b. only other magnets.
c. anything made of metal.
d. things that are not too heavy.
What makes magnets repel from each other?
Magnets repel when you try to put the South pole with the South pole and the North pole with the north pole.