December 2010 - Physics Subject Test

<p>Acceleration due to gravity isn’t disputed. I was just corrected. It’s 1/9g.</p>

<p>The mass doesn’t change (that’s one of the info in the problem, it says that M stays the same, only R changes) , so the A = 1/9a …
And as for the half covered lens, there was only the choice of “full object” there was no “full object but less bright” answer, if I recall corectly?</p>

<p>The distance the rock/bucket will fly after a worker kicks it is 1m.</p>

<p>okay ill change it to full object</p>

<p>Are you sure about the bucket one? What was the question for that again?</p>

<p>It’s 2m. It takes one second for an object to fall 5m (more like 4.9 but w/e). G is 10 m/s^2, meaning at the end of the second it’s going 10. The average is 5.</p>

<p>the question said that the bucket falls 5 m / second. The horizontal velocity was 2m/sec and the distance from the ground was 5 m. So isn’t the answer 2 m?</p>

<p>If the height is 5m it takes it half a second to fall down. </p>

<p>0.5 x 2m/s = 1m</p>

<p>0 = 5 - 5t^2
t = 1 s</p>

<p>Undisputed answers so far:</p>

<p>antimatter question: positron
water is boiling: upper most straight part
Index of refraction: sin 60 / 1.5
Given initial velocity, mass, and stopping time: 1, 2, and 3
Force x time = change in momentum
What led to the nuclear model: gold foil experiment
Skydiver jumping off of a plane: potential energy > kinetic energy
Throw ball a up and ball b down at same initial velocity. Whats the velocity of ball a: v (same as ball b)
Skydiver jumping off of a plane: potential energy > kinetic energy
Half covered lense: full object, but decreased intensity
Index of refraction is 4/3: wavelength is 3/4
Which waves will result in the least disturbance: 6 + (1/2)wavelength
Man is standing underneath water: only choice 1 (the bird and the tree appear to be higher than they actually are)
Particle question where you know the rotational speed of the giant ball with a slit in it: you can only find the speed of the particles
Students climbing stairs - heaviest one
Pv = nrt : t increases as q increases
Heaviest: neutron
Convex mirror: virtual image
Convex lense: real image both small and big
acceleration due to gravity: 1/9
Theta and initial velocity one: Just increase the initial velocity
Worker kicks the bucket: 2 m</p>

<p>Disputed questions:</p>

<p>None</p>

<p>But it doesn’t take half a second to fall, it takes 1 second. The acceleration of gravity being 10 m/s^2 doesn’t mean it takes 1 second to fall 10 m, it means after one second it’s falling AT 10 m/s.</p>

<p>What was the answer to the pulley one? 0.8 Kg or 1.2 Kg?</p>

<p>Has to be electric field near point charge?
Has to be magnetic field near bar magnet?</p>

<p>^i put 1.2</p>

<p>Yes; yes</p>

<p>the circuit one, which ammeters measured highest/lowest - <a href=“http://■■■■■■/Cnmma[/url]”>http://■■■■■■/Cnmma&lt;/a&gt;&lt;/p&gt;

<p>More answers:</p>

<p>Direction of electric field vector at P: west
Direction of force on negative point charge: East</p>

<p>Ammeters are highest at 1 and 2
Lowest at 4 and 5</p>

<p>Increase thickness by 4 and decrease heat transfer by 1/4?</p>

<p>Confirm amneters question given the above picture, but I think they were numbered differently on the test.</p>

<p>12 watts to 3 watts?</p>

<p>I think so too (heat transfer) .
Although I’m pretty sure the d is still 1 :smiley: .
Aren’t the ammeters highest at 3 and lowest at 1 and 2 ? When R is lower, I is higher… ?</p>

<p>Undisputed answers so far:</p>

<p>antimatter question: positron
water is boiling: upper most straight part
Index of refraction: sin 60 / 1.5
Given initial velocity, mass, and stopping time: 1, 2, and 3
Force x time = change in momentum
What led to the nuclear model: gold foil experiment
Skydiver jumping off of a plane: potential energy > kinetic energy
Throw ball a up and ball b down at same initial velocity. Whats the velocity of ball a: v (same as ball b)
Skydiver jumping off of a plane: potential energy > kinetic energy
Half covered lense: full object, but decreased intensity
Index of refraction is 4/3: wavelength is 3/4
Which waves will result in the least disturbance: 6 + (1/2)wavelength
Man is standing underneath water: only choice 1 (the bird and the tree appear to be higher than they actually are)
Particle question where you know the rotational speed of the giant ball with a slit in it: you can only find the speed of the particles
Students climbing stairs - heaviest one
Pv = nrt : t increases as q increases
Heaviest: neutron
Convex mirror: virtual image
Convex lense: real image both small and big
acceleration due to gravity: 1/9
Theta and initial velocity one: Just increase the initial velocity
Worker kicks the bucket: 2 m
Must be electrical field: point charge
Must be magnetic field: bar magnet
Ammeter question (based on drawing from [ImageShack&#174</a>; - Online Photo and Video Hosting](<a href=“ImageShack - Best place for all of your image hosting and image sharing needs):%5DImageShack®”>ImageShack - Best place for all of your image hosting and image sharing needs):slight_smile:
Highest: 1 and 2
Lowest: 4 and 5
Vector direction for electric field: West
Vector direction for negative point charge: East
Mass of object in pulley problem: 1.2 Kg</p>

<p>Disputed questions:</p>

<p>None</p>

<p>Dakilica, </p>

<p>For the ammeter question:</p>

<p>The current is the highest near the battery (answers first question)</p>

<p>For the second question: in a parallel circuit, voltage is the same but current is divided based on the resistance. Thus, the one with a lower resistance will receive more current.</p>

<p>Was it a concave or convex mirror?</p>