PROBLEMS 1 How many neutrons are contained in 2 kg Mass of Ans 1 198 x 1027 one neutrons 1 67 x 10 27 kg 2 How many electrons mass 9 1 x 10 31 kg would balance one proton mass 1 67 10 27 kg Ans 1835 3 How many electrons should be added into a body to make it heavier by 5 nanogram Mass of one Ans 5 49 x 1018 electron is 9 1 x 10 31 kg 4 Convert a velocity of 20 m 8 1 in kilometre per hour Ans 72 km hr 5 Convert an acceleration of 50 kilometre per hour Ans 0 003858 m 8 21 into metre per sec 6 Convert an acceleration of 20 ms 2 in to kilometre per hour Ans 2 592 x 105 km h 2 7 How many metre are there in one i Gigametre iii Hectometre ii Femtometre iv Exametre v Nanometre vi Picometre Ans i 10 ii 10 15 iii 102 iv 1018 v 10 9 vi 10 8 How many gram are there in one i Teragram ii Microgram iv Petagram iii Attogram v Decagram vi Centigram Ans i 10 2 ii 10 6 iii 10 18 iv 1015 v 10 9 vi 10 21 9 How many centimetre are there in one i Fermi Micron iii v Astronomical unit ii Angstrom unit iv Light year Ans i 10 13 ii 10 8 iii 10 4 iv 9 5 1017 v 1 496 x 1013 are there in a mass of 2 Ans 2 x 1027 ng 10 How many nanogram exagram 11 What is the relation terametre 12 How many picometre are gigametre 13 Obtain a relation between between femtometre and Ans 1 fm 10 27 Tm contained in one Ans 1024 microsecond and