Samantha's Science Unit Test

When we name a force (like gravity or a magnetic force) what other information should we include about?

- What way does the force point? (Upward or downward) - An example - If it's balanced or unbalanced - What two objects does it act between!! - Touching or non-touching!

What does a force act between?

A force acts between two objects.

What is gravity? What objects does gravity act between?

An object falls because Earth pulls the object toward it with the force of gravity. Gravity always acts between Object 1 = Earth and Object 2 = Anything on Earth!

What is evidence of a balanced force? What is evidence of an unbalanced force? What is evidence that the forces acting on an object have changed from balanced to unbalanced?

Evidence of a balanced force is when an object is not moving. Evidence of an unbalanced force is when an object starts moving. If forces exerted on an object are balanced, and then a force changes, the forces become unbalanced, which can cause the object to start moving.

What types of objects can magnets attract

Magnets can attract some metal objects. Iron is a metal that most magnets attract.

How do magnets attract and repel other magnets?

Magnets have positive and negative poles. If a positive and a positive are facing each other, they repel. If a negative and a negative are facing each other, they repel to. If a negative and a positive are facing each other, they attract.

What is a non-touching force? Can a magnetic non-touching force act on ALL other objects?

Non-touching forces can act between magnets and some, but not all, other objects.

Do all forces happen between objects that are touching?

Nope! Some forces happen between objects that are touching. Other forces happen between objects that aren't touching.

Why does the train change from floating to falling?

The train changes from floating to falling because the magnetic force gets weaker when the conductor turns off the repelling force from the tracks. When the magnetic force gets weaker, the forces are UNBALANCED. Gravity overpowers the magnetic force and the train falls down.

Why does the train fall?

The train falls so we know that a force is acting on it because it moved. We know the force that is acting on the train when it falls is gravity. Gravity is a NON-TOUCHING downward force that acts on everything on earth. Forces act between two objects, and in this case gravity acts between earth and the train.

Why does the train rise?

The train rises because there must be a PUSH force acting on it that pushes it away from the tracks.

Why does the train rise without anything touching it?

The train rises without anything touching it because a non-touching force is acting it. The non-touching force is a REPELLING magnetic force between the train tracks and the train that PUSHES the train upward.

Why does the train float, even though gravity is acting on it?

There is more than one force acting on the train when it floats. Both gravity and the magnetic force are acting on the train at the same time. The train floats without moving because the two forces acting on it are BALANCED. When an object has balanced forces acting on it, it doesn't move.

What are multiple forces?

Two forces can be exerted on an object at the same time.

How do we know that a force is acting on an object?

When an object starts moving or stops moving, that is evidence that a force has acted on it.

How do we create balanced forces?

When two forces are exerted on an object in opposite directions, the forces can be balanced. We create balanced forces by making sure the forces are EQUAL and pointing in OPPOSITE directions.