The Average Intensity of Sunlight Impinging on Earth Is Measured $1.4 \mathrm {~kW} / \mathrm { m } ^ { 2 }$

Multiple Choice

The average intensity of sunlight impinging on Earth is measured to be about $1.4 \mathrm {~kW} / \mathrm { m } ^ { 2 }$ What is the power of sunlight emitted by the sun? $\text { (Earth-Sun distance } = 1.5 \times 10 ^ { 8 } \mathrm {~km} \text {, Earth radius } = 6.4 \times$ $\left. 10 ^ { 3 } \mathrm {~km} \right)$

A) $7.2 \times 10^{14} \mathrm {~W}$
B) $4.0 \times 10 ^ { 26 } \mathrm {~W}$
C) $7.6 \times 10 ^ { 8 } \mathrm {~W}$
D) $3.2 \times 10 ^ { 22 } \mathrm {~W}$