Complete the sentences to explain why a main sequence star remains stable:
"A main sequence star is stable because the inward gravitational force, caused by ________, is balanced by the outward force of radiation pressure, which is produced by the energy released during nuclear ________."
Write down the equation that links distance travelled (sss), speed (vvv), and time (ttt).
The mean distance between the Sun and Neptune is 4.5×1012 m4.5 \times 10^{12}\text{ m}4.5×1012 m. Light travels at a speed of 3.0×108 m/s3.0 \times 10^8\text{ m/s}3.0×108 m/s. Calculate the time taken for sunlight to reach Neptune.
Practise AQA GCSE Physics Forces and motion with exam-style questions for Foundation and Higher tier. 83 questions covering Describing motion along a line, Forces, accelerations and Newton's Laws of motion, and Forces and braking, matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.