Download Warm-Up Questions

Warm-Up Questions
• What is a force?
• What kind of different forces affect you each
and every day?
What is a force?
• Any push or pull
• Generally changes the motion of an object
– Can stop, change the speed, and change the
direction of a moving object (accelerate)
• Acceleration = change in velocity
– Velocity = speed & direction
• Can act in any direction!
Warm-Up Question
• What do forces do to objects?
• List at least one example of when you have
experienced inertia…
Forces continued…
• What happens to an object with no forces
acting upon it?
– Object will continue to move at the same speed in
the same direction
– Otherwise known as…..
• Inertia
– The resistance of an object to change its motion
How do we measure force?
• with Force Scales
• Units for Force?
– In Newtons
• named after Sir Isaac Newton
The first type of force we will be
measuring…
Gravitational Force
• What is gravity?
– The natural force of attraction between any two
massive bodies
• (all objects pull on one another)
– Every object has its own gravitational force
• Depends on mass and distance of object(s)!
• Earth’s gravity acts downward toward the center of the
Earth
Questions
• How would walking up 300 flights of stairs in a
sky scraper affect your body weight?
• Hypothetically speaking, would there be a
greater gravitational pull on a microscopic
particle by….?
Time to read…
• Read Gravity Article
• Make note of:
– Isaac Newton’s findings
– Galileo’s findings
– The circumstances that would change the strength
of the pull of gravity on our bodies
When measuring…
• What does it mean for your measurements to
be accurate? Precise?
• Accurate
– how closely a measured value agrees with the
correct value
• Precise
– how closely individual measurements agree with
each other
Questions
• You measure the force of a mass on your force
scale to be 4 N, 5N, and 4.3 N. The actual
force from the mass is 10 N. Were your
measurements precise, accurate, both, or
neither?
Questions
• You measure the force of a mass on your force
scale to be 8.2 N, 11.3N, and 9.8 N. The actual
force from the mass is 10 N. Were your
measurements precise, accurate, both, or
neither?
Questions
• You measure the force of a mass on your force
scale to be 3 N, 7N, and 15 N. The actual force
from the mass is 10 N. Were your
measurements precise, accurate, both, or
neither?
Questions
• You measure the force of a mass on your force
scale to be 9 N, 9.7N, and 10.4 N. The actual
force from the mass is 10 N. Were your
measurements precise, accurate, both, or
neither?
Accurate vs. Precise
Making Force Scales
• Use pages 9-10 for assistance
Questions
• What does calibrate mean? What are some
things that you calibrate?
• Calibrate
– Mark off intervals on an instrument (adjusting the
instrument) so that it can be used to measure
something correctly
– Helps make your precise measurements accurate
Gravitational Constant
• the force of gravity on Earth is 0.01 N on each
gram of mass
– .01 N/g
– 1 g = 1 mL = .01 N
How to measure using a graduated
cylinder?
• Measure from the bottom of the meniscus!
Video Questions
• Why does Earth’s gravity have the greatest
affect on us?
• If you were to travel from the Earth to the
Moon, would your mass change?
• What would happen if you dropped a
crumpled piece of paper and a flat piece of
paper in a vacuum?
Mythbusters
Buttered Side Up or Down?
• Knowing what you know about gravity and
how it pulls on different masses, do you think
a piece of bread with one side buttered will
always land on the buttered side?
Algebra Review
• W = mk … Solve for m
• W = mk … Solve for k
• m = W/k … Solve for W
• m = W/k … Solve for k
• Plug W=mk into the equation F=ma
Warm-Up Question
• When measuring, what does it mean to obtain
results in real vs. ideal situations?
Simulation -- Exit Slip
• Write a general rule for the gravitational force
between objects, that explains the effect of
mass and distance.