An unmanned interstellar vessel is traveling through deep space where there is no atmosphere. Initially, it is moving at a constant speed in a straight line.
State whether a continuous force is necessary to keep the vessel moving at this constant speed.
The vessel's rear ion engines are now turned on, ejecting high-speed exhaust gases directly backward. State the effect of this action on the motion of the vessel.
Eventually, the vessel enters the atmosphere of a gas giant planet with its engines turned off. Under these conditions, suggest two physical effects that the atmosphere has on the vessel.
183 exam-style questions on CIE IGCSE Physics 1.5.1a Forces, resultant force and motion. Each one has a worked solution and a mark scheme showing where the marks go.