It takes light from the Sun approximately 8 minutes to reach the Earth. The speed of light is 3 × 10 8 m s (this is 3 followed by eight zeros). Use this data to calculate the approximate distance of the Earth from the Sun.

Given, Speed of light v = 3 × 10 8 m s Time taken by light from the sun to reach the earth t = 8 minutes = 8 × 60 s = 480 s Let s be the distance of the earth from the sun. Speed is the distance covered by a body in unit time. Speed = distance time Therefore, distance = speed × time s = v × t s = 3 × 10 8 × 480 s = 1440 × 10 8 m s = 1 . 44 × 10 8 km The approximate distance between the earth and the sun is 1 . 44 × 10 8 km .

E M B I B E

NEW SCIENCE In Everyday Life>Chapter 12 - Time and Motion>Exercises>Q 1

EASY

7th CBSE

IMPORTANT

Earn 100

The distance between the Earth and the moon is $384, 400 km$ . It takes four days for a spacecraft to travel from the Earth to the moon. Calculate the speed of the spacecraft. (Hint: Take $1$ day = $24$ hours).

Important Questions on Time and Motion

EASY

7th CBSE

IMPORTANT

NEW SCIENCE In Everyday Life>Chapter 12 - Time and Motion>Exercises>Q 2

It takes light from the Sun approximately

8 minutes

to reach the Earth. The speed of light is

3 \times 10^{8} \frac{m}{s}

(this is

3

followed by eight zeros). Use this data to calculate the approximate distance of the Earth from the Sun.

EASY

7th CBSE

IMPORTANT

NEW SCIENCE In Everyday Life>Chapter 12 - Time and Motion>Exercises>Q 2

What would be the speed required to travel the distance of two thousand kilometres in two and a half hours? Which would be the most ideal mode of travel, if cost is not a factor?