Q1.
10⁵ seconds ≈ 1.16 days and 10⁶ seconds ≈ 11.57 days. Think of some events or phenomena whose time is of the order of (i) 10⁵ seconds and (ii) 10⁶ seconds. Write them in scientific notation.
Answer
| Order | Event or phenomenon | Time in scientific notation |
|---|---|---|
| 105 s (about a day) | One full day and night (24 h) | 8.64 × 104 s |
| A train from Delhi to Chennai, about 33 hours | 1.2 × 105 s | |
| A cyclone crossing a coastline, about a day | ≈ 1 × 105 s | |
| A five-day Test match (5 × 6 h of play) | 1.1 × 105 s | |
| 106 s (about 12 days) | A hen's egg hatching, 21 days | 1.8 × 106 s |
| One phase of the Moon, new moon to new moon, 29.5 days | 2.5 × 106 s | |
| Recovering from a viral fever, about 10 days | 8.6 × 105 s | |
| A school examination period of two weeks | 1.2 × 106 s |
Useful conversions:
1 day = 8.64 × 104 s
1 week = 6.05 × 105 s
1 month ≈ 2.6 × 106 s
1 year ≈ 3.15 × 107 s
1 day = 8.64 × 104 s
1 week = 6.05 × 105 s
1 month ≈ 2.6 × 106 s
1 year ≈ 3.15 × 107 s
Why it happens: "of the order of 105" does not mean exactly 1,00,000 seconds — it means anything from about 3 × 104 to 3 × 105, which is why a 24-hour day and a 33-hour train journey both qualify. That looseness is deliberate. When quantities span twenty powers of 10, as in this chapter, sorting them into the right power is far more informative than pinning down the coefficient.