Physics workshop Witnessing Wonders

On 16 September, 2017, 2 teachers ( Ms. P. Yogeshwari and Mr. Pallab Roy) of the Physics department were nominated to attend a Physics workshop titled "Witnessing Wonders at the Sadhu Vaswani International School for Girls. The workshop was held in collaboration with BVM-IAPT Anvenshika, under the guidance of resource person Mr. Samar K. Bagchi, Ex-Director, Birla industrial & Technological Museum, Kolkata). Mr. Bagchi has conducted more than 250 hands-on workshops for science teachers throughout India.

The workshop was very effective for teachers needing creative science-integrated strategies to teach the subject in a way that students enjoy it. We learnt how to draw a continuous connection between teaching concepts of science with hands'-on experiments. Teachers were shown how to supplement their lectures in the classroom using low-cost teaching aids. The activities we observed were as follows.

Hot Air Expansion - The speaker ignited the uppermost part of a cylindrical tea bag and in a few seconds the ash rose quickly from the bottom. This way the experiment demonstrated that hot air being lighter rises.

Law of Inertia- here He a coin was placed on a stiff card covering an empty glass tumbler. When the card was flicked with the finger the coin placed over it fell into the tumbler. This was caused by the property of inertia, wherein an object tends to remain in its position of rest/motion.

Newtons 2rd Law of Motion-Conservation of linear momentum- Here it was explained with the help of coins, that the sum of the momenta of two objects before collision is equal to the sum of the momenta after collision. Hence, linear momentum remains conserved.

Conservation of angular momentum- In this the speaker tied a match box with a thread and whirled it around. As the radius decreased, the angular velocity increased.

Newtons 3rd law of Motion- Mr. Bagchi inflated a balloon and fixed it on a straw which passed through which the thread tied to the neck of the balloon passed. Next he removed the thread tied on the neck of the balloon. The air that escaped from the mouth of the balloon pushed the balloon in the opposite direction which proved that every action has an equal and opposite reaction.

Archimedes Principle- Here he suspended a stone tied with a thread into a beaker containing water. There was an apparent loss of weight of the stone. This showed that the up thrust (buoyant force) is equal to the weight of the water displaced. This is the Archimedes Principle, which has several applications. It is used for designing ships and submarines, the lactometer, hydrometer and also determining the density of liquids.

Centrifugal, Centripetal force Here a piece of thread was taken and the speaker tied a small stone at one end, holding the other end of the thread. He then whirled it round. The stone followed a circular path towards the centre with a velocity of constant magnitude. This force is called the centripetal force. He performed the experiment with different lengths of thread to observe the magnitude of the force. It was demonstrated that force increases when the length of the rope reduces (mv2/r).

Ms. P. Yogeshwari.