गति | दूरी | विस्थापन | कक्षा 9 NCERT विज्ञान (Vigyan) | Chapter 8 | Doubtnut | Ruchi Ma'am | 8 PM

A machine P can print one lakh books in 8 hours, machine Q can print the same number of books in 10 hours while machine R can print them in 12 hours. All the machines are started at 9 a.m. while machine P is closed at 11 a.m. and the remaining two machines complete the work. Approximately at what time will the work be finished? a. 11 : 30 a.m. b. 12 noon c. 12 : 30 p.m. d. 1 p.m.

A clock is displaying correct time at 9am on Monday. If the clock loses 12 minutes in 24 hours, then the actual time when the clock indicates 8:30 pm on Wednesday of the same week is (a) 8 pm (b) 7 pm (c) 9 pm (d) 8:59 :45 pm

P and Q are 120 km apart. A starts from P towards Q at 6 am. B starts from Q towards P at 11 am on the same day. A is 50% faster than B. They cross each other at 8 pm. In reaching his destination, how many more hours than A, will B take? 8 b. 9 c. 10 d. 12

Two cars A and B leave Delhi at 8:30 a.m. and 9 a.m. for Shimla, respectively. They travel at the speeds of 40km/h and 50 km/h respectively. How many kilometres away from Delhi will the two cars be together? दो कारें A तथा B दिल्ली से क्रमशः 8: 30 a.m एवं 9 a.m में शिमला जाने के लिए खुलती है | वे क्रमशः 40 किमी/घंटा तथा 50 किमी/घंटा की चाल से यात्रा करती हैं | दोनों कारें दिल्ली से कितने किलोमीटर की दूरी पर एक साथ होंगी ?

The face-centred unit of nickel has an edge length of 352.39 pm. The density of nickel is 8.9 g cm^(-3) . Calculate the value of Avogadro's number. The atomic mass of nickel is 58.7 and 1 pm is equal to 10^(-10) cm.

A and B at a distance of 1.7 km apart and they start running towards each other at a speed of 8m/s and 9 m/s respectively. After how much time, will they meet each other? A और B 1.7 किमी की दूरी पर अलग हैं और वे क्रमशः 8 मीटर /सेकंड और 9 मीटर / सेकंड की गति से एक दूसरे की ओर दौड़ना शुरू करते हैं। कितने समय के बाद, वे एक दूसरे से मिलेंगे?