An unmanned deep-space probe is travelling through space with no resultant force and no resultant moment acting on it. Which statement about the probe is correct?
Its direction of travel is changing.
It is in equilibrium.
Its speed is decreasing.
Its speed is increasing.
245 exam-style questions on CIE IGCSE Physics 1.5 Forces, covering 1.5.1a Forces, resultant force and motion, 1.5.1b Load–extension graphs and the spring constant, 1.5.1c Friction and drag, 1.5.1d Force, mass and acceleration, 1.5.1e Motion in a circular path, 1.5.2a Moment of a force, 1.5.2b Principle of moments and equilibrium, and 1.5.3 Centre of gravity and stability. Each one has a worked solution and a mark scheme showing where the marks go.