A cylindrical disc of thickness 1 cm
A cylindrical disc of thickness 1 cm is made by melting two solid cylinders of radii 4 cm and 5 cm, and length 6 cm and 4 cm, respectively. The radius of the new cylinder is:
दो ठोस सिलेंडर जिनकी त्रिज्या क्रमशः 4 सेमी और 5 सेमी और ऊँचाई क्रमशः 6 सेमी और 4 सेमी है, को पिघलाकर एक नया सिलेंडर बनाया जाता है जिसकी मोटाई 1 सेमी है।
नए सिलेंडर की त्रिज्या कितनी होगी?
Detailed Solution & Logic
Correct Answer:
14 cm
r1=4,cm, h1=6,cm, r2=5,cm, h2=4,cm
Total volume=$ \pi(4^2\times6+5^2\times4) $
$ =\pi(96+100)=196\pi $
Let radius of new disc=R, thickness=1,cm
$ \pi R^2 \times 1 = 196\pi $
$ R^2=196 $
R=14, cm
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