Physical Science

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3rd Grade Science › Physical Science

Questions 1 - 10
1

Mindy needs to get iron filings out of a pile of sand, rice, and dirt in science class. The iron filings are tiny and fine so they blend in and disappear with the mixture. What would be the best tool to remove the filings from the sand?

Sifter

Tweezers

Magnet

Microscope

Explanation

Using scientific knowledge about magnets and their capabilities can help solve problems that we face in the real-world. If Mindy needs to remove the iron filings, she can use a magnet to remove them from the sand, dirt, and rice. The sand, dirt, and iron filings would slip through the sifter because they are so tiny, tweezers would not be able to sort the small filings out of the mixture, and a microscope would help Mindy see the iron filings better but would not help her separate them.

2

Brad and Brian must separate a mixture prepared by their teacher. She asks them which items in the container could be removed by using a magnet and why. The things they have are toothpicks, sand, pebbles, marbles, iron filings, paper clips, chocolate chips, broken crayons, and bits of notebook paper.

Which items can they remove with a magnet, and why?

Pebbles and chocolate chips because they are all magnetic

Marbles, iron filings, and bits of notebook paper because they are all magnetic

Iron filings and paperclips because they are all magnetic

Borken crayons, pebbles, and sand because they are all magnetic

Explanation

Brad and Brian can use their scientific knowledge of magnets to determine which objects can be removed from the mixture. The items that can be removed have the quality of being magnetic. Bran and Brian can remove the iron filings and paperclips from the mix because they are both metal and magnetic. The other objects are made of materials that would not be attracted to the magnet.

3

Nadine has a crane with a big magnet. She lowers the crane's magnet over a pile of garbage. Which object(s) are strongly attracted to the magnet?

A plastic fork

A metal spoon

A sock

A paper plate

Explanation

Magnets attract objects made of certain materials. Objects that are strongly attracted to magnets will stick to them. The plastic fork, sock, and paper plate will not stick to the attraction. These objects are not strongly attracted to the magnet. The metal spoon will stick to the magnet. This object is strongly attracted to the magnet.

4

Two magnets with opposite poles are placed two feet away from each other. As the magnets are moved closer together, what is most likely going to happen?

They will not affect each other and remain where they are.

They will change colors as they get closer to each other.

They will get attached as they get closer.

They will repel each other as they get closer.

Explanation

Magnets have a magnetic field that attracts other magnetic objects, so because of this, they attach when they are close enough. If two magnets are moved closer and closer together, they will eventually reach each other's magnetic field and be very attracted to each other. Once this happens, the magnets will move towards each other and become attached.

5

Gregory and Morgan have two magnets. They are confused about why the magnets will not go together. They push them together with all of their might, but they still will not connect.

Why won't the magnets go together?

The magnets have the same poles (charges) being pushed together.

The magnets have opposite poles (charges) being pushed together.

The magnets are broken.

The magnets need to be activated before they will work correctly.

Explanation

There is a cause and effect relationship between magnets that is being explored in this question. Gregory and Morgan are experiencing the effect of magnets having the same poles or charges faced towards each other. If the North end of both magnets or South ends of both magnets were pushed together, the magnets would repel. If opposite sides were being pushed towards each other, they would be attracted and connected.

6

Two magnets with opposite poles are placed two feet away from each other. As the magnets are moved closer together, what is most likely going to happen?

They will not affect each other and remain where they are.

They will change colors as they get closer to each other.

They will get attached as they get closer.

They will repel each other as they get closer.

Explanation

Magnets have a magnetic field that attracts other magnetic objects, so because of this, they attach when they are close enough. If two magnets are moved closer and closer together, they will eventually reach each other's magnetic field and be very attracted to each other. Once this happens, the magnets will move towards each other and become attached.

7

Jill wants to investigate how objects move and see if she can make correct predictions. She knows she will have to observe the object's motion. She wants to see how high different bouncy balls will go on the same surface.

If Jill performs the fourth trial, what prediction can be made about "Ball 3"?

Screen shot 2020 06 15 at 2.32.25 pm

"Ball 3" will most likely bounce the highest distance during Trial 4.

"Ball 3" will most likely bounce the shortest distance during Trial 4.

There is no way to predict what "Ball 3" will do during Trial 4.

The ball will no longer bounce because it has been used too many times.

Explanation

Jill can make predictions about what will happen in future trials because there are patterns in motion that data helps us to recognize. "Ball 3" bounced the shortest height in all of the previous tests, so, likely, it will again bounce the shortest height. Using patterns and data can help support the prediction that she is making.

8

What would be the most appropriate tool to measure the weight or mass of the marbles in the data table below?

Screen shot 2020 05 21 at 1.03.20 pm

A scale

A ruler

A beaker

A measuring cup

Explanation

This data table shows the marble's weight is in grams. To measure the marble accurately, a scale should be used to find its weight or mass. A beaker and measuring cup would be more appropriate for liquids, and a ruler measures length. A scale or balance would be the best option for weight or mass.

9

Grant wants to investigate how objects move and see if he can make correct predictions. He knows he will have to observe the object's motion. He wants to see if a soccer ball will travel further on artificial turf or real grass.

What will Grant need to measure to determine which surface the soccer ball travels furthest on?

Grant will measure the weight of each type of grass.

Grant will measure the time it takes for each ball to go across the grass.

Grant will measure the distance the balls traveled on each type of grass.

Grant will measure the speed of the ball as it moves across the grass.

Explanation

Grant will be investigating whether a soccer ball travels further on artificial turf or real grass. The keyword "further" in that statement gives a clue to which answer choice would be the correct measurement. The only answer choice that measures distance is, "Grant will measure the distance the balls traveled on each type of grass.". This choice would collect information about each grass type and the distance the balls traveled so they can be compared.

10

How will the motion of the individual change due to the unbalanced forces?

Resist, Tug-Of-War, Cartoon, Strong

When the three players start to tug against the individual, he will move towards them and eventually lose the game.

When the three players start to tug against the individual, he will move away from them and eventually win the game.

When the three players start to tug against the individual, he will move towards them and eventually win the game.

When the three players start to tug against the individual, he will move away from them and eventually lose the game.

Explanation

This graphic represents an unbalanced force. One individual player versus three players on the opposite team is not an equivalent amount of force or strength. The single-player will move towards the group of three when the pulling starts because they have more power than one player alone. The lone player will eventually lose the game when crossing over the center point due to an equal amount of force.

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