Question

If the sun is 150 million km away from the earth, how long does it take sunlight to reach the earth
0.5 s
1500 s
45 s
500 s

Answer 1

Answer on Question #46982, Physics, Optics

If the sun is 150 million km away from the earth, how long does it take sunlight to reach the earth

0.5 s

1500 s

45 s

500 s

Solution:

Given:

$$\begin{array}{l} d = 150 \cdot 10^{6} \mathrm{~km} = 150 \cdot 10^{9} \mathrm{~m}, \\ v = 3 \cdot 10^{8} \mathrm{~m/s} \text{ is the speed of light}, \\ t = ? \\ \end{array}$$ $$\text{time} = \frac{\text{distance}}{\text{speed}}$$

We will divide the distance to the Sun by the speed of light, which will give us the answer in seconds:

$$t = \frac{d}{v} = \frac{150 \cdot 10^{9}}{3 \cdot 10^{8}} = 500 \mathrm{~s}$$

Answer: 500 s