<Tr> <Td> Second law: </Td> <Td> In an inertial reference frame, the vector sum of the forces F on an object is equal to the mass m of that object multiplied by the acceleration a of the object: F = ma . </Td> </Tr> <Tr> <Td> Third law: </Td> <Td> When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body . </Td> </Tr> <Table> <Tr> <Th> Classical mechanics </Th> </Tr> <Tr> <Td> F → = m a → (\ displaystyle (\ vec (F)) = m (\ vec (a))) Second law of motion </Td> </Tr> <Tr> <Th> <Ul> <Li> History </Li> <Li> Timeline </Li> </Ul> </Th> </Tr> <Tr> <Td> Branches (show) <Ul> <Li> Applied </Li> <Li> Celestial </Li> <Li> Continuum </Li> <Li> Dynamics </Li> <Li> Kinematics </Li> <Li> Kinetics </Li> <Li> Statics </Li> <Li> Statistical </Li> </Ul> </Td> </Tr> <Tr> <Td> Fundamentals (show) <Ul> <Li> Acceleration </Li> <Li> Angular momentum </Li> <Li> Couple </Li> <Li> D'Alembert's principle </Li> <Li> Energy <Ul> <Li> kinetic </Li> <Li> potential </Li> </Ul> </Li> <Li> Force </Li> <Li> Frame of reference </Li> <Li> Impulse </Li> <Li> Inertia / Moment of inertia </Li> <Li> Mass </Li> <Li> Mechanical power </Li> <Li> Mechanical work </Li> <Li> Moment </Li> <Li> Momentum </Li> <Li> Space </Li> <Li> Speed </Li> <Li> Time </Li> <Li> Torque </Li> <Li> Velocity </Li> <Li> Virtual work </Li> </Ul> </Td> </Tr> <Tr> <Td> Formulations (show) <Ul> <Li> Newton's laws of motion </Li> <Li> Analytical mechanics <Ul> <Li> Lagrangian mechanics </Li> <Li> Hamiltonian mechanics </Li> <Li> Routhian mechanics </Li> <Li> Hamilton--Jacobi equation </Li> <Li> Appell's equation of motion </Li> <Li> Udwadia--Kalaba equation </Li> <Li> Koopman--von Neumann mechanics </Li> </Ul> </Li> </Ul> </Td> </Tr> <Tr> <Td> Core topics (show) <Ul> <Li> Damping (ratio) </Li> <Li> Displacement </Li> <Li> Equations of motion </Li> <Li> Euler's laws of motion </Li> <Li> Fictitious force </Li> <Li> Friction </Li> <Li> Harmonic oscillator </Li> </Ul> <Ul> <Li> Inertial / Non-inertial reference frame </Li> <Li> Mechanics of planar particle motion </Li> </Ul> <Ul> <Li> Motion (linear) </Li> <Li> Newton's law of universal gravitation </Li> <Li> Newton's laws of motion </Li> <Li> Relative velocity </Li> <Li> Rigid body <Ul> <Li> dynamics </Li> <Li> Euler's equations </Li> </Ul> </Li> <Li> Simple harmonic motion </Li> <Li> Vibration </Li> </Ul> </Td> </Tr> <Tr> <Td> Rotation (show) <Ul> <Li> Circular motion </Li> <Li> Rotating reference frame </Li> <Li> Centripetal force </Li> <Li> Centrifugal force <Ul> <Li> reactive </Li> </Ul> </Li> <Li> Coriolis force </Li> <Li> Pendulum </Li> <Li> Tangential speed </Li> <Li> Rotational speed </Li> </Ul> <Ul> <Li> Angular acceleration / displacement / frequency / velocity </Li> </Ul> </Td> </Tr> <Tr> <Td> Scientists (show) <Ul> <Li> Galileo </Li> <Li> Newton </Li> <Li> Kepler </Li> <Li> Horrocks </Li> <Li> Halley </Li> <Li> Euler </Li> <Li> d'Alembert </Li> <Li> Clairaut </Li> <Li> Lagrange </Li> <Li> Laplace </Li> <Li> Hamilton </Li> <Li> Poisson </Li> <Li> Daniel Bernoulli </Li> <Li> Johann Bernoulli </Li> <Li> Cauchy </Li> </Ul> </Td> </Tr> <Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> </Table> <Tr> <Th> Classical mechanics </Th> </Tr>

When can a moving object have its acceleration opposite to the direction of motion