RS Aggarwal Class 8 Math Second Chapter Exponents Exercise 2B Solution

EXERCISE 2B

(1) Write each of the following numbers in standard form:

(i) 57.36 = 5.736 × 10

(ii) 3500000 = 3.5 × 10⁶

(iii) 273000 = 2.73 × 10⁵

(iv) 168000000 = 1.68 × 10⁸

(v) 4630000000000 = 4.63 × 10¹²

(vi) 345 × 10⁵ = 3.45 × 10⁷

(2) Write each of the following numbers in usual from:

(3) (i) The height of Mount Everest is 8848 m. write it in standard form.

Solution: the height of Mount Everest = 8848 m

= (8.848 × 1000) m = (8.848 × 10³) m.

(ii) The speed of light is 300000000 m/sec. Express it in standard form.

Solution: The speed of light = 300000000 m/sec

= (3 × 100000000) m/sec = (3 × 10⁸) m/sec

(iii) The distance from the earth to the sun is 149600000000 m. Write it in standard form.

Solution: The distance between earth and sun = 149600000000 m

= (1.496 × 100000000000) m = (1.496 × 10¹¹) m

(4) Mass of earth is (5.97 × 10²⁴) kg and mass of moon is (7.35 × 10²²) kg. What is the total mass of the two?

Solution: The total mass = {(5.97 × 10² × 10²²) + (7.35 × 10²²)} kg

= {(597 + 7.35) × 10²²}kg = 604.35 × 10²²kg

(5) Write each of the following numbers in standard form:

(7) Write each of the following numbers in usual form: