Balanced & Unbalanced Forces
Press, throw, and stomp are examples of a push or a pull?
Press, throw, and stomp are examples of a push.
Name the three types of bridges that we studied in class.
Arch, pillar, suspension bridges.
Which has more friction? A piece of steel or a piece of wood?
A piece of wood.
What is the term for magnets that move toward another magnet?
attraction
Why is it hard to win a tug-of-war against a group of teachers?
Teachers have a lot of friction.
Tow, yank, and grab are examples of a push or a pull?
Tow, yank, and grab are examples of a pull.
Why are pillar and arch bridges stronger than a simple board bridge?
The pillars and arches supply a force from below to push up on the bridge and support its weight. The simple board bridge does not have that support.
Why does sand paper have more friction than steel? Explain.
Sand paper has a much rougher surface. Steel is much smoother and less bumpy which causes less friction.
What is the term for magnets moving away from each other?
repelling
Why do hoppers hop off the table?
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.
Why force does a foot put on a water balloon to make it pop?
The force is a push.
Which bridge has supports that push off the sides of the structure? It is often see with two supports shaped in a curve underneath the bridge.
An arch bridge.
Sandpaper sliders don’t slide very fast because ___?
Sandpaper creates a lot of friction.
Magnets don’t have to be touching to push and pull each other. What is the term for this?
Working at a distance.
How could you use a magnet to move a train? Explain
Trains can be moved by the bottom of the train being repelled by the magnets in the tracks.
Why won't a watermelon burst when you step on it? Explain.
The watermelon pushes up against the force of the foot stepping down. The force of the watermelon is more than that of the foot.
Which bridge is supported by pulling downwards from the towers, sort of like a hammock? Name one famous bridge that uses this type of support.
A suspension bridge. Golden Gate Bridge.
What are some things you could do to go down a slide faster?
You could make the slide more steep. You make the slide more slippery by adding water or oil or by making the slide out of a material that doesn’t have a lot of friction. You could also wear clothes or ride on a mat made of a material that doesn’t have a lot of friction.
Magnets attract objects that contain what?
Iron
Name three things on the playground that uses force.
Sliding down the slide, swinging, playing basketball (shooting the ball in the basket) etc.
What was special about the one final rubber band that caused the watermelon to burst?
The last rubber band was special because adding it made the force of the rubber bands stronger than the force of the rind.
Why was the suspension bridge a good design for connecting San Francisco and Sausalito?
The suspension bridge was long enough to connect the two cities. Pillars weren’t possible because the water was very deep and ships needed to pass underneath
Imagine a student sliding down a slide. If the friction force is stronger than the force of gravity, what will happen? Why?
The student will stop sliding because the friction force is pushing against the student and the gravity force isn’t strong enough to keep pulling the student down the slide.
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.
How could you use a magnet to open a door. Explain.
You can create a lock that is either pushed or pulled open with a magnet.