Newton’s Laws of Motion Sci. 2-2 Newton’s Laws of Motion Pages 43-51

A. Newton’s First Law of Motion- An object at rest remains at rest and an object in motion remains at constant speed and in a straight line unless acted on by an unbalanced force.

B. Friction is usually the unbalanced force that effects Newton’s 1st Law. Friction causes the motion to slow or stop.

C. Inertia- to resist any change in motion C. Inertia- to resist any change in motion. Small mass objects have less inertia than large mass objects.

D. Newton’s Second Law of Motion- The acceleration of an object depends on the mass of the object and the amount of force applied.

1) Acceleration decreases as mass increases, acceleration increases as mass decreases 2)If the push (force) is the same, heavy objects move slower than lighter objects. 3) More acceleration if larger force (push harder).

Formula for Newton’s 2nd Law- a= acceleration, m= mass, F= force a=F/m or F= m x a 1) 1N= 1 kg x m/s/s

Newton’s Third Law of Motion- Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. 1) forces act in pairs to cause motion but not all force pairs cause motion.

1) more momentum- harder to stop Momentum- a property of a moving object that depends on the object’s mass and velocity 1) more momentum- harder to stop 2) more mass- more momentum

3) momentum is transferred from the 1st object to the 2nd