06 Feb Review: Newton’s First Law
Review:
Newton’s First Law: If the Net Force on an object is zero, it will not accelerate.
If an object is at rest, it will remain at rest. If an object is in motion, it will move
with constant velocity, that is, at constant speed in a straight line.
Newton’s Second Law: If the Net Force on an object is not zero, it will accelerate
in the direction of the net force.
???????????? = ??? ?????
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Equations of Motion
????? = ? = ????????
???? Velocity includes direction indicator, usually a + or – sign.
???????????? = (?? ― ??)
?
Part 1 Newton’s 1st and 2nd Law of Motion
Open PhET Simulation Forces and Motion, Basics (see Canvas).
Link: https://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-
basics_en.html
Select the 4th window labeled Acceleration twice.
Leave Friction setting at the default position.
Check all the boxes.
Using the arrow keys gradually apply a force to the right on the crate and
determine the maximum force that can be applied without overcoming the
force of static friction to start the crate moving. Once the crate starts
moving, pause the simulation.
What was maximum force of static
friction?
What was the force of kinetic friction once
the crate starts moving?
What applied force got the crate
moving? (this should the the current
applied force setting)?
What is the net force on the crate?
What is the acceleration of the crate?
Show that this demonstrates ? = ?
?.
https://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-basics_en.html
link address above to answer the equations for the above simulation
unit 2:
1.) How much momentum does a go-kart have if it has a mass of 76 kg and is moving with a speed of 25 m/s?
2.) Your professor decides to break the Guinness Book of World Records for bungee jumping. She goes to the Macau Tower in China where the current record is held. She leaps from a height of 233 meters. If her weight is 60 kilograms, what would be her potential energy be just prior to jumping relative to the ground?
3.) Which worker does more work, Andy who applies a force of 100 N to lift a box 1.00 m upward or Bella who applies a force of 25.0 N to push the box up a frictionless ramp a distance of 4.00 m?
4.) A 1 kg rock is dropped from some height “h” and attains a speed of 34 m/s just before it hits the ground. From what height was the rock dropped? Ignore air resistance.
5.) The specific heat capacity of silver is 230 J/(kg⋅°C). How much heat energy (in Joules) is needed to raise the temperature of a 30-kg piece of silver from 0°C to 100°C.
