* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Force, mass, and acceleration
Survey
Document related concepts
Hunting oscillation wikipedia , lookup
Coriolis force wikipedia , lookup
Relativistic mechanics wikipedia , lookup
Classical mechanics wikipedia , lookup
Center of mass wikipedia , lookup
Newton's theorem of revolving orbits wikipedia , lookup
Fictitious force wikipedia , lookup
Jerk (physics) wikipedia , lookup
Equations of motion wikipedia , lookup
Seismometer wikipedia , lookup
Centrifugal force wikipedia , lookup
Rigid body dynamics wikipedia , lookup
Modified Newtonian dynamics wikipedia , lookup
Classical central-force problem wikipedia , lookup
Transcript
Force, Mass, and Acceleration Sir Isaac Newton discovered the link Acceleration • Acceleration- rate at which an object’s speed changes • Amount that speed increases compared to how long it takes • Acceleration = change in speed/ change in time A = v2- v1/t2- t1 • Units meters per second per second m/sec2 • Deceleration- slowing down (negative acceleration) • Zero acceleration- object moving at constant speed • Acceleration of gravity- 9.8 m/s2 –Object in free- fall in a vacuum • Different on the moon or different planets Speed vs. time graph • Positive slope= positive acceleration (speeding up) • Negative slope = negative acceleration (slowing down) • No slope =no acceleration (constant speed) Newton’s Laws of Motion 1. An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion will continue with constant speed and direction unless acted on by an unbalanced force. – Things tend to keep doing what they’re doing until a force is applied Newton’s Laws of Motion 2. The acceleration of an object is directly proportional to the force acting on it and inversely proportional to its mass –Force causes an object to accelerate, while the object’s mass resists acceleration Newton’s Laws of Motion 3. Whenever one object exerts a force on another, the second object exerts and equal and opposite force on the first –For every action, there is an equal and opposite reaction –If you push on a wall, you feel the wall pushing back on your hand Force • Any action that has the ability to change motion (push, pull, etc) • Force doesn’t always change motion (pushing down on a table) Force • Units –Pounds (lbs) –Newtons (N) •4.48 newtons in a pound The Newton • 1 N = 1 kg x 1 m/s2 • A force of 1 newton causes a 1kilogram mass to have an acceleration of 1 m/s2 Mass • Amount of “stuff” or matter in an object • Resists the action of forces, making objects harder to accelerate Weight vs. Mass • Weight - force of gravity acting on an object –N or lbs • Mass is independent of gravity –2.2 lbs = 1 kg –30 lb child has a mass of about 14 kg • Units of force = lbs and N • Units of Mass= kilograms (kg) Newton’s 1st Law • Thing tend to keep doing what they’re doing unless acted upon by an outside force • Law of Inertia • Inertia - property of an object to resist changing its state of motion • Big trucks have more inertia than small cars • Which is harder to push: a ball with a mass of 1 kg or a ball with a mass of 100 kg? • Once started moving, which is harder to stop? Newton’s 2nd Law • Force causes an object to accelerate, while the object’s mass resists acceleration • Force causes acceleration • Mass resists acceleration • Acceleration = force/mass a = F/m a = acceleration F = force (N) m = mass (kg) 2 (m/s ) a = F/m • Must be sure to have m/s2 for acceleration • Must have N for force • Must have kg for mass Balanced and Unbalanced Forces • Net Force- total of all forces acting on an object • When forces are balanced- Net force= 0 –Equilibrium = no change in motion (object at rest stays at rest, object in motion stays in motion) • For motion to change- forces have to be unbalanced • Force acting on one side of objects has to be greater than force acting on other side