What is Sami's problem with the catapult?

• The magnets are sticking together, so projectile isn't thrown.

• The magnets are sticking together, so the projectile is thrown too far.

• The magnets are repelling away from each other, so the projectile is thrown the opposite way.

Tags

NGSS.MS-ETS1-1

NGSS.MS-PS2-1

NGSS.MS-PS2-2

What question should Sami ask to investigate the problem?

• How are the magnets on the catapult interacting?

• How does the length of the arm change the machine?

• Where can Sami set up the catapult?

• Why do magnets push away when the poles are facing the same direction?

Answer explanation

The correct question to ask would be about how the magnets on the catapult are interacting, since the arm is connect to the projectile and the magnet. The magnets are attracted to each other, which keeps the arm from moving.

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

NGSS.MS-PS2-2

• Add the correct force arrows to Magnet #1 and Magnet #2 to show how they are interacting.

a

b

←

→

↑

↓

Answer explanation

The arrows need to be pointing toward each other because the magnets are being pulled together.

Tags

(MS-PS2-3)

• 
  Since the magnets are stuck together, Magnet #1 and Magnet #2 must be touching on ​the ​ (a)   poles. Magnets ​ (b)   when the ​north pole of one magnet faces the ​ (c)   pole of another magnet. There is a​ (d)   magnetic force between Magnet #1 and Magnet #2

• opposite
• north
• attract
• south
• pulling
• same
• repel
• pushing

Answer explanation

Opposite poles attract (N-S) and the same poles repel (S-S) or (N-N).

Attraction is a pulling force. Repelling is a pushing force.

Tags

(MS-PS2-3)

This design works because the arm with magnet #1 is being pulled towards the _____, letting the arm swing.

• Magnet #2

• Base

• Projectile

• Catapult Arm

Answer explanation

The arm needs to be pulled upward to throw an object. Magnetic force pulls the arm toward the hinge, which lets the object be thrown.

Tags

(MS-PS2-3)

How do the magnets need to interact for the catapult to work?

• No interaction needed
• Opposite poles

  (N-S)

• Same poles

  (N-N) or (S-S)

• Random poles

Tags

NGSS.MS-PS2-3

• Add the correct force arrows to Magnet #1 and Magnet #2 to show how they are interacting.

d

c

↑

←

→

↓

Tags

(MS-PS2-3)

If the magnets are kept in facing ​ (a)   poles (so they ​ (b)   ), but put on different parts of the catapult system, the attractive force will pull ​ (c)   (which is glued to the catapult arm) up toward ​ (d)   . The object will be thrown.

• opposite
• attract
• Magnet #1
• Magnet #2
• same
• repel

Answer explanation

Opposite magnetic poles attract (pull together). The same magnetic poles repel (push apart).

The arm needs to get pulled up toward the other magnet to throw an object, so the magnets must have opposite poles.

Tags

(MS-PS2-3)

Why does moving the magnets farther apart from other affect how the catapult works?

• Moving the magnets farther apart INCREASES the force between the magnets.

• Moving the magnets farther apart DECREASES the force between the magnets.

• Moving the magnets farther apart would not effect the force of the magnets, so something else must be wrong.

Answer explanation

The increase in the distance between the magnets in the 3rd catapult is the reason it doesn't work. As magnets get farther away, their pulling and pushing force gets weaker.

Tags

(MS-PS2-3)

Will these two magnets attract or repel?

• Attract
• Repel

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5