Download Which will fall faster?

2/17 & 2/18 - 8th Grade Agenda
Learning Objective: Learn about Gravity
Collect HW: Reading & Notetaking p.177 – 178
Balloon Rocket Lab
Textbook Reading p. 389 - 392
HW: Reading & Notetaking p.180 – 181
Reminder Science Fair Board due 2/24 (50
Points)
Daily Reflection
• Prompt: Write 3 question about gravity.
For an object to stay in motion, a
orce has to act on it.
F_____
The tendency of an object to
resist change in its motion is
nertia
called I________
Which will fall faster?
• Will a lighter object fall faster or a heavier
object?
• Will a piece of paper fall faster or a text
book? Why?
• Lets try.
Which will fall faster?
• Will a penny fall faster or stack of a3
pennies? Why?
• Lets try.
The force that pulls objects
toward each other is called
ravity
G______
If two balls with different masses
are dropped to the ground in a
vacuum, would they fall exactly
the same rate?
• Yes
The amount of matter in an
ass
object is called M_____
Why does a leaf fall more slowly
than an acorn?
• Because of air
resistance.
• In a vacuum,
both would fall
at the same
speed
What is the terminal velocity
(final velocity) of a sky diver?
• 122 mph
• 50% of terminal
velocity is reached
in 3 seconds
• 90% of terminal
velocity is reached
in 8 seconds.
• 99% of terminal
velocity is reached
in 15 seconds.
How many meters will an object
fall in 1 second?
• 9.8 meters
• Every 1 second, speed will increase by 9.8
m/s
How much do objects accelerate
as they fall?
• On earth objects accelerate at 9.8 m/s2
• After 1 second, object will be falling at 9.8 m/s
• After 2 seconds, object will be falling at (9.8 + 9.8) 19.6
m/s
• After 3 seconds, object will be falling at (9.8 + 9.8 + 9.8)
29.4 m/s
• The velocity will continue to increase until it reaches
terminal velocity
• For a sky diver the terminal velocity is about 56 m/s (124
miles / hr)
What is the difference between
weight and mass?
• Weight is a measure of the force of gravity
on an object, and mass is a measure of
the amount of matter in that object.
The law of universal gravitation
ravity
states that the force of G______
ll
acts between a___
objects in the
universe.
• Even a book is exerting a gravitational
force on you.