Transcript Force 2-2 Notes

Sci. 2-2
Newton’s Laws of
Motion
Pages 43-51
A. Newton’s First Law of MotionAn 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
st
Newton’s 1 Law. Friction causes
the motion to slow or stop.
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).
nd
2
E.Formula for Newton’s
Law- a=
acceleration, m= mass, F= force
a=F/m or F= m x a
1) 1N= 1 kg x m/s/s
F.Newton’s Third Law of MotionWhenever 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.
G.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