StudentAidUnit 2: Logarithms — Exercise 2 1
9th Class Mathematics · Unit 2: Logarithms
2.1.1.Express the following numbers in scientific notation: (i) 2000000 (ii) 48900 (iii) 0.0042 (iv) 0.0000009 (v) 73 × 10^3 (vi) 0.65 × 10^2
Result
(i)
2000000 = 2 × 106
(ii)
48900 = 4.89 × 104
(iii)
0.0042 = 4.2 × 10-3
(iv)
0.0000009 = 9 × 10-7
(v)
73 × 103 = 7.3 × 104
(vi)
0.65 × 102 = 6.5 × 101
2.1.2.Express the following numbers in ordinary notation: (i) 8.04 × 10^2 (ii) 3 × 10^5 (iii) 1.5 × 10^-2 (iv) 1.77 × 10^7 (v) 5.5 × 10^-6 (vi) 4 × 10^-5
Result
(i)
8.04 × 102 = 804
(ii)
3 × 105 = 300000
(iii)
1.5 × 10-2 = 0.015
(iv)
1.77 × 107 = 17700000
(v)
5.5 × 10-6 = 0.0000055
(vi)
4 × 10-5 = 0.00004
2.1.3.The speed of light is approximately 3 × 10^8 metres per second. Express it in standard form.
Given
Speed of light
3 × 108 m/s
Result
Standard form
300{,}000{,}000 m/sec
2.1.4.The circumference of the Earth at the equator is about 40075000 metres. Express this number in scientific notation.
Given
Circumference
40075000 m
Result
Scientific notation
4.0075 × 107 m
2.1.5.The diameter of Mars is 6.7779 × 10^3 km. Express this number in standard form.
Given
Diameter of Mars
6.7779 × 103 km
Result
Standard form
6779 km
2.1.6.The diameter of Earth is about 1.2756 × 10^4 km. Express this number in standard form.
Given
Diameter of Earth
1.2756 × 104 km
Result
Standard form
12756 km