Dr. K C Trikha and N K Sehgal Solutions for Chapter: Work and Energy, Exercise 10: Something to know

Name a device which converts electrical energy into light energy.

Name a device which converts sound energy into electrical energy.

Name a device which converts chemical energy into electrical energy (Battery/Fan).

Kshitij visited his native village during the summer vacation. While taking a stroll in the field, he saw a boy aiming his catapult at a bird. He asked the boy not to do so and to use his energy for helping, rather than harming others. 
Which quality of Kshitij's behaviour do you appreciate? 

Kshitij visited his native village during the summer vacations. While taking a stroll in the field, he saw a boy aiming his catapult at a bird. He asked the boy not to do so and to use his energy for helping, rather than harming, others. 
What kind of energy is possessed by the stretched string of the catapult?

Kshitij visited his native village during the summer vacations. While taking a stroll in the field, he saw a boy aiming his catapult at a bird. He asked the boy not to do so and to use his energy for helping, rather than harming, others. 
What kind of energy is possessed by the stone when it gets released from the catapult?

Kshitij visited his native village during the summer vacation. While taking a stroll in the field, he saw a boy aiming his catapult at a bird. He asked the boy not to do so and to use his energy for helping, rather than harming others. 
Do you think that Kshitij did the right thing by asking the boy not to hit the bird?

Kshitij visited his native village during the summer vacation. While taking a stroll in the field, he saw a boy aiming his catapult at a bird. He asked the boy not to do so and to use his energy for helping, rather than harming others. 
Give your suggestions about how one can use his/her energy for helping, rather than harming, others.