A planet orbits a nearby star.
The power output of the star is 1.2 × 1026 W. The average distance of the planet from the star is 1.8 × 1011 m.
The intensity of radiation, III, at a distance d d\,d from a star of power P P\,P can be calculated using the equation:
I=P4πd2 I = \frac{P}{4 \pi d^2} I=4πd2PCalculate the intensity of the radiation from the star at the planet's orbit.
Give your answer to 2 significant figures and state the appropriate unit.
28 exam-style questions on Edexcel GCSE Physics 7.1 The Solar System and gravity. Each one has a worked solution and a mark scheme showing where the marks go.