After being released, a 20 kg curling stone continues in a straight line. At the start of a 10 s interval its speed is 2.5 m s−12.5\ \mathrm{m\,s^{-1}}2.5 ms−1. At the end of the interval its speed is 1.5 m s−11.5\ \mathrm{m\,s^{-1}}1.5 ms−1.
What is the magnitude of the mean resultant force on the curling stone?
0.10 N0.10\ \mathrm{N}0.10 N
5.0 N5.0\ \mathrm{N}5.0 N
20 N20\ \mathrm{N}20 N
2.0 N2.0\ \mathrm{N}2.0 N
103 exam-style questions on Edexcel GCSE Physics 2.3 Forces and Newton's laws, covering 2.3.1 Newton's first law, 2.3.2 Newton's second law, and 2.3.3 Weight and gravitational field strength. Each one has a worked solution and a mark scheme showing where the marks go.