| KEPLER | Johannes ---, found laws of motion |
| INERTIA | Subject of one of Newton's laws of motion |
| ISAAC | First name of the scientist whose three laws of motion form the basic principles of classical mechanics (5) |
| NEWTON | Surname of the compiler of the three laws of motion published in 1687 (6) |
| EDMOND | Forename of the astronomer who used Newton's laws of motion to predict the return of the comet that was later named in his honour (6) |
| VAINNEWTON | Egotistical describer of laws of motion? |
| ISAACNEWTON | Formulator of laws of motion (5,6) |
| HALLEY | Astronomer who used Newton's laws of motion to predict the periodical comet that bears his name (6) |
| SECOND | Newton's ___ law of motion states that the rate of change of momentum of a body is directly proportional to the external force acting on it (6) |
| THRUST | Propulsive property, as of a jet or rocket engine, explained by Newton's third law of motion (6) |
| AXIOM | Newton's law of motion, e.g. |
| FORCE | Vector in Newton's second law of motion |
| EQUAL | "To every action there is always opposed an - reaction", according to Newton's third law of motion (5) |
| BAIL | Described in Law 8 of the Laws of Cricket, either of the two crosspieces bridging the stumps of a wicket (4) |
| BRAHE | Wealthy Danish astronomer whose lifetime of astronomical observations provided the basis for Kepler's laws of planetary motion (5) |
| LENNOXES | Some in-laws of Mary, Queen of Scots |
| PERPETUALMOTION | Violation of the first and second laws of thermodynamics |
| OVERRULE | Invalidate one of the laws of cricket, apparently (8) |
| MOTION | Subject of three laws of Newton |
| OVER | Set aside part of the laws of cricket? (8) |
