Term
| Define and give units of speed |
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Definition
| speed is how fast, distance/time, units m/s or cm/s |
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Term
| Define and give units of instantaneous speed, velocity, acceleration |
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Definition
| its the speed, velocity, or acceleration at an insant, units still m/s, m/s, and m/s^2 |
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Term
| Define and give units of velocity |
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Definition
| it is how fast with direction, vector quantity, units m/s |
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Term
| Define and give units of acceleration |
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Definition
| its the change in velocity/change in time, units m/s^2 |
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Term
| Define and give units of distance |
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Definition
| speedxtime, scalar quantity, units m |
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Term
| Define and give units of displacement |
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Definition
| how far relative to a starting position, change in x, units m |
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Term
| Define and give units of density |
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Definition
| mass/volume, units kg/m^3 |
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Term
| describe the physics of a set of keys thrown straight upward |
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Definition
| the keys are thrown up with an initial velocity, the gravitational force (acceleration due to gravity) slows the keys down, where t-top=v(subnot)/g, then the keys speed back up as they fall down and strike the hand with the same speed that they left the hand. |
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Term
| How far objects move dropped from rest in free fall |
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Definition
∆y=v(subnot)t-1/2gt^2
an object moves a distance ∆y in free fall, which is equal to the initial velocity times time subtracted from half of the the gravitational constant times time squared. |
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Term
| How fast objects move dropped from rest in free fall |
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Definition
either equation v=v(subnot)-gt
or v^2=v(subnot)^2-2g∆y
Both equations can determine how fast, the first equation is how fast in regards to initial velocity subtracted by the gravitational constant times time
The second equation is the initial velocity squared subtracted by 2 times the graviational constant times ∆y |
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Term
| Compare and contrast scalars and vectors |
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Definition
| Both scalars and vectors are quantities with magnitude, but only vectors are quantities with magnitude and direction. |
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Term
| Examples of scalars and vectors |
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Definition
Scalars= temp, speed, distance, mass
Vectors= force, velocity, acceleration, displacement |
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Term
| What objects of a car cause acceleration? |
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Definition
Gas pedal, brakes, steering wheel, tires, etc---all are accelerators because they change speed or direction
Acceleration is a vector quantity |
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Term
| Speedomoter or velocitomer in the car's dashboard? |
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Definition
| Speedomoter because it only gives magnitude, not direction, scalar quantity |
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Term
| Define and give examples of proportional |
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Definition
technique for comparing quantities, if quantity A increases, then quantity B also increases
distance α time
amnount of water in the tub α time water running
Circumfrence α diameter |
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Term
| Define and give examples of inversely proportional |
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Definition
if quantity A increases, then quantity B decreases at the same rate
P α 1/V
Money in your acct α 1/checks you write |
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Term
| What kinematic parameters are changing when an ojbect is in free fall dropped from rest? |
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Definition
| Time, velocity, displacement, NOT Acceleration |
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Term
| Acceleration due to gravity |
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Definition
| Any free-falling object is falling under the influence of gravity. All free falling objects dropped from rest accelerate at 9.8m/s^2 |
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Term
| A box has volume 75 cubic inches, convert to cubic meters and centimeters |
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Definition
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Term
| Compare d=st and d=(1/2)gt^2 |
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Definition
first equation is scalar, finding distance only with magnitude
second equation is finding distance with acceleration, which makes it a vector quantity |
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Term
| After 2 seconds, a freely falling objects will have a speed of ?? and have dropped ?? m |
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Definition
v=v(subnot)-gt
=0-(9.8)(2)
=-19.6m/s
∆y=v(subnot)t-1/2gt^2
=(0)(2)-1/2(9.8)(2)^2
=-17.6m |
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Term
| discuss the three kinematic formulas |
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Definition
v=v(subnot)+at
∆x=v(subnot)+1/2at^2
v^2-v(subnot)2=2a∆x
The first equation come about by the defn of acceleration and can be used to solve for any of the variables
The second equation is a substitution of v into a ∆x equation so that there is no v
The third equation is a substitution into the previous equation for t so that there is no time variable |
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