Balloon से Glass उठाओ | Lift a glass with a balloon | BURN AND LIFT | Science Experiment #shorts

An experment is performed to find the refractive index of glass using a travelling mircroscope. In this experiment distances are measured by

A glass rod is rubbed with a silk cloth and inflated rubber balloon is rubbed with a woollen cloth. Now , out of glass rod, silk cloth, rubber balloon and woollen cloth : which two objects acquire positive charge ?

A glass rod is rubbed with a silk cloth and inflated rubber balloon is rubbed with a woollen cloth. Now , out of glass rod, silk cloth, rubber balloon and woollen cloth : which two objects acquire negative charge ?

(i) In an experiment, appearance of concentric rings on watch glass against light indicates the presence of ________ (ii) In an experiment, production of boiled off air indicates presence of__________

A balloon leaves from a point P rises at a uniform speed. After 6 minutes, an observer situated at a distance of 450 sqrt3 metres from point P observes that angle of elevation of the balloon is 60^@ .Assume that point of observation and point P are on the same level. What is the speed (in m/s) of the balloon? एक मुब्बारा एक समान गति से बिन्दु P से छोड़ा जाता है। 6 मिनट पश्चात, बिन्दु P से 450 sqrt3 मीटर दूरी पर एक समीक्षक है जो देखता है कि गुब्बारे का उन्नयन कोण 60^@ है। मान लीजिए कि समीक्षा बिन्दु तथा बिन्दु P एक ही स्तर पर है। गुब्बारे की गति [मी/ से.में] क्या है?