Post on 29-Dec-2015
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AIM: Describe the factors that effect the strength of gravity and how inertia differs from gravity?
OBJ: Given notes, images and activity sheet SWBAT describe the factors that effect the strength of gravity and how inertia differs from gravity with 70% accuracy
DN: HW check- Earth in Space Activity Sheet
ACT: Introduction to Gravity and Inertia (notes)Complete Earth’s Motions Activity Sheet
HW: Text, read 16-19, Complete Gravity & Motion Activity Sheet; Work on Astronomy Activity Sheet; Astronomy Exam, Dec 19. Weather & Climate (Red) Textbooks due Dec 18,19.
GRAVITYForce: a push or pull
Gravity: attractive force between objects containing mass [In reality, gravity is the warping of spacetime by objects in the universe].
Gravitational Force Unit: newton, N
Two factors affect gravity: 1) mass of the object’s, 2) distance between objects.
F(g) = M1 x M2_
d2
Gravity
Gravity
MassMass: amount of matter (atoms) in an object
Weight: force of gravity on an object’s mass. Weight = mass x gravity
Note: object’s mass doesn’t change but
object’s weight changes due to change in gravity because planets/moon vary in size.
DistanceGravity decreases, as distance increases
Gravity increases, as distance decreases
Inverse relationship
distance
gra
vity
InertiaInertia: tendency of an object to resist a change in motion.
Newton’s first law of motion: Objects at rest, remain at rest
Objects in motion, remain in motion (at constant speed & direction) . . . unless acted on by a force.
Inertia
Orbital MotionOrbit is due to two (2) factors:
1] gravity
2] inertia
inertia