Gravity
Section 3.2
Gravity
Law of Gravitation- any two masses exert
an attractive force on each other
– Gravity is one of the 4 basic forces :
electromagnetic force, the strong nuclear
force, and the weak nuclear force.
– Gravity is a long range force
Due to gravity all objects fall with the
same acceleration regardless of mass
All things fall at the same rate???
Things fall at the same rate because
a = F/m Force is greater with greater
mass, so acceleration remains constant
http://www.glenbrook.k12.il.us/GBSSCI/P
HYS/mmedia/newtlaws/efff.html
– Without air resistance
http://www.glenbrook.k12.il.us/GBSSCI/P
HYS/mmedia/newtlaws/efar.html
– With air resistance
All things fall at the same rate??
http://www.teachersdomain.org/resource
s/phy03/sci/phys/mfw/galmoon/index.ht
ml
http://www.teachersdomain.org/resource
s/phy03/sci/phys/mfw/zweightlessness/in
dex.html
Weight
Weight- gravitational force exerted on an object
Weight decreases as an object moves away from
Earth because gravity decreases
Weight results from a force; mass is how much
matter an object contains
Objects in the space shuttle are in free fall
because they have no force supporting them
http://www.physicsclassroom.com/Class/circles/
U6L4d.html
Weight
Projectiles – have horizontal and vertical
velocities due to gravity and follow a
curved path
http://www.glenbrook.k12.il.us/gbssci/phy
s/Class/vectors/u3l2a.html
Acceleration toward the center of a curved
path is called centripetal acceleration-
caused by centripetal force –unbalanced F
Why can’t we feel the motion of
the earth?
http://www.teachersdomain.org/resources
/phy03/sci/phys/mfw/galthought/index.ht
ml
How does low gravity impact climate?
http://www.teachersdomain.org/resources
/ess05/sci/ess/eiu/extemp/index.html