How can magnet do work?

How can magnet do work?

Materials needed

• · Magnet
• · Steel ball

Procedure

1. Place the magnet on on the table.
2. Place the steel ball on the table about 2--3 cm (1 in.) from the end of the magnet.
3. Let go of the steel ball.
4. What happened?
5. What is work, and how was work done in step 3?

For problem solvers:

 find a variety of magnets. Predict which ones are strongest and weakest, and lay they out in order from strongest to weakest, according to your predictions. Then continue with the above activity, comparing the strength of these magnets. Which one seems to attract the steel ball from the farthest distance?
Were your predictions accurate? Compare size with strength. Are larger magnets always stronger than smaller magnets?

Teacher information

Work was dined in this section's "to the teacher” as moving something (a force acting through a distance). The magnet should cause the steel ball to roll toward it. If this did not happen, try putting the steel ball a bit closer to the magnet or find a stronger magnet.
A paper clip can be used in the place of the steel ball if necessary.

How does a nail change as it is driven into a board?

How does a nail change as it is driven into a board?

Materials Needed

• · Hammer
• · Nail, at least 5cm (2 in.) long
• · Board, at least 4 cm (1 1/12 in.) thick
• · Pounding surface

Procedure

1. Place the board on a good pounding surface such as another board, a stack of newspapers, or concrete.
2. Pound the nail at least 2.5 cm (1 in.) into the board. Do not pound it all the way in.
3. As soon as you stop pounding, feel the nail. What difference do you notice in the nail?
4. Pull the nail out of the board with the hammer.
5. As soon as you get the nail out of the board, feel it again.
6. What difference do you notice in the nail by feeling it? What can you say about this?

For problem solvers: 

rib your hands together, hard and fast. Do you feel a temperature change? How is this similar to what you experienced with the nail in the above activity?

Teacher information

As the nail is pounded into the board, some of the energy from the hammer is changed to heat energy due to friction between the nail and the board. As the nail is removed from the board, friction again changes some of the energy to heat. If the nail is pulled out quickly, the heat might be even more noticeable than when it was pounded in.

Teacher information

As the nail is pounded into the board, some of the energy form the hammer is changed to heat energy due to friction between the nail and the board. As the nail is pulled out quickly, the heat might be even more noticeable than when it was pounded in.

How do molecules behave when heated?

How do molecules behave when heated? 

Materials needed

• Chalk or masking tape

Procedure

1. Have several students stand in a group.
2. Mark a border on the floor around the group with chalk or tape. Leave a few inches between the group and the border all the way around.
3. Ask students to move around slowly. Everyone should move constantly, but no one should move fast and there should be no pushing and shoving. They are to try to stay within the border marked on the floor.
4. Now instruct those in the group to move a bit faster. They are still to try to stay within the border.
5. Continue speeding up the movement of the group until they can no longer remain within the line marked on the floor.
6. Discuss what happened as those in the group increased their speed. Ask how this relates to the movement of molecules as temperature is increased.

rocket ballon

Rocket balloon 

Material:

1. Balloon
2. Plastic straw
3. Thread
4. Cello tape

final assembly

slip a plastic straw in a thread

Add hold thread tightly

source:http://www.arvindguptatoys.com/

SUDARSHAN CHAKRA

   SUDARSHAN CHAKRA

   SUDARSHAN CHAKRA

Cut two sticks from a broomstick - one long 15 cm and the other short 6-cm. Tie the sticks tightly with a string as shown in the drawing. Poke a hole in the rubber cap of an injection bottle, or else, in the eraser from your geometry box. Insert the rubber cap in the long broomstick. Now place the joint of the sticks on your right hand index finger and rotate the assembly as shown. You will be surprised to see that the sticks rotate around your finger like a Sudarshan Chakra without falling. As a matter of fact, the faster you rotate the sticks, the more stable and balanced is the assembly.  This simple toy will give children a good feel for Centrifugal and Centripetal force.

Source:http://www.arvindguptatoys.com