SEISMIC SLEUTHS Part 1Newton’s Laws

EARTHQUAKES AND PHYSICS?

• Newton’s laws • Liquefaction lab • Smart Sitting• Energy and Quakes

CAN BUILDINGS BE MADE SAFER?

• Building Fun• Structural Reinforcement• BOSS• Earthquake in a Box• Building Challenge• Find and Fix the Hazards• Strengthening your

House

Newton’s Laws of Motion:

• _____________________• Objects keep on doing what they are

doing.

http://www.physicsclassroom.com/mmedia/newtlaws/cci.cfm

______ is directly related to _____.• The greater the mass the greater the tendency

to ___________change of an object’s motion.

• objects will continue to do as they are doing __________ __________.

_________________: if the net force on an object is _______ (at rest or moving at a constant velocity)

________ friction

• _______ friction results when the surfaces of two objects are at rest relative to one another

2nd law: ______ _______: something that

disturbs an object’s equilibrium (net force changes an object’s velocity or acceleration)

• Need to be able to find the net force (sum of all forces on an object) since net force causes an object’s acceleration

http://www.physicsclassroom.com/mmedia/kinema/avd.cfm

2nd Law: acceleration of an object is proportional to the mass of the object being accelerated

• __________ – a is in m/s/s – m is in kg, – F is kgxm/s/s or

________

• __________ (weight)– Gravity (9.8 m/s/s)

http://www.physicsclassroom.com/mmedia/newtlaws/efar.cfm

Unbalanced force• The _________ force is

cancelled by the force of _________.

• The book is sliding to the right but there is _____force in that direction.

• Because _________ friction is currently the only horizontal force it will cause the book to come to a stop

___________ Friction

• If a car slams on its brakes and skids to a stop (without antilock brakes), there is a sliding friction force exerted upon the car tires by the roadway surface.

Causes of friction:

• When the high points of each surface touch they bond, you must break these bonds to move one of the pieces (origin of static friction)

• As surfaces move across each other, _________ forces continue to attract between high points, resulting in the weaker kinetic friction

• Air drag (any fluid) depends on speed of the motion (getting larger as speed increases)

• size and shape of object• _________ of fluid

Forces• ________________

The contact force that acts to oppose sliding motion between surfaces. ____________ to the surface _____________ the direction of sliding

• ______________ The contact force exerted by a surface on an object. _______________ to and away from the acceleration of the object barring any resistive forces.

3rd law:

• __________________________________________________________________________

http://www.physicsclassroom.com/mmedia/momentum/crete.cfm