‘प्रथम’ बाल विज्ञान मेला : हिंदी पीडीऍफ़ पुस्तक – पत्रिका | ‘Pratham’ Bal Vigyan Mela : Hindi PDF Book – Magazine (Patrika)
Pustak Ka Vivaran : Saral Machine Insanon dvara Istemal kiye Jane vale sabase purane aujar hai. Sakht dande ki Madad se bhari Patthar ko ulatana, dharadar vastu se kisi cheej ko katana, pahiye ki Madad se bhari bojh ko dhona, Chimate ki Madad se kisi cheej ko pakadana jaisi Aadim tarakeeben saral Masheenon ke udaharan hai. Saral Masheenen svayan koi bal Paida……….
Description about eBook : Simple machines are the oldest tool used by humans. Primitive methods such as overturning a heavy stone with the help of hard poles, cutting something from a sharp object, carrying a heavy load with the help of a wheel, holding something with the help of tongs are examples of simple machines. Simple machines themselves generate no force ……….
