Physics Test - how smart are you?

Originally posted by Ramned
Good - #2 - it is a medium, not air necessarily, but you're right.

Explain why on #1.

Done.

Originally posted by Ramned
Ay, you missed 2. (But you did get the sky is blue question - ROYGBIV. You see colors that are reflected, not absorbed - good.)

#1 , #5.

Someone answered #5 - weight is in Newtons.

If someone can answer #1 correctly (and explain since there are only 2 choices) I will put 10 even harder ones up right now.

No, you see the colors that are reflected instead of passing through the air without being affected.

Originally posted by AThousandYoung
No, you see the colors that are reflected instead of passing through the air without being affected.

That is what I am saying. You see a green shirt, because it reflects green and absorbs all others.

You are correct on #1 - velocity is a stronger factor in kinetic energy than mass.

Next set of questions to follow.

Originally posted by Ramned
That is what I am saying. You see a green shirt, because it reflects green and absorbs all others.

You are correct on #1 - velocity is a stronger factor in kinetic energy than mass.

Next set of questions to follow.

That's not what happens in the air though. But whatever.

Harder!

1. When looking into a concave mirror, is the image you see
A) Virtual B) Real C) Possibly both, real or virtual.
2. True or False: Convex mirrors magnify the images.
3. What produces a higher pitch at the fundamental frequency, a closed pipe or an open pipe? Why?
4. When you see a longitudinal wave, what is the relation between the wave's energy and direction?
5. What is the term that describes the point on a standing wave where little or no movement occurs?
6. True or False: A car going 80 m/s on a circular racetrack is accelerating.
7. Suppose you threw a rock upward at an angle of 45 degrees. When the rock reaches the top of its projectory, are the forces acting upon the rock: A) Horizontal B) Vertical C) Horizontal and Vertical D) No forces are acting on the rock at this point.
8. Why is it colder at night when there are no clouds versus when there are clouds? Explain.
9. An elevator takes 18 passengers up 9 meters every second. The total weight of the passengers is 600 Newtons. Assuming gravity is 10 m/s, what is the Power that the elevator is using?
10. What are the 2 (or 3) factors of a string that cause different pitches when plucked?

If anyone gets all 10 of those, I will put up 5 more questions, the hardest (conceptual) questions I can think of! Appears that AThousandYoung has common sense / is a good physicist.

Originally posted by Ramned
[b]Harder!

1. When looking into a concave mirror, is the image you see
A) Virtual B) Real C) Possibly both, real or virtual.
2. True or False: Convex mirrors magnify the images.
3. What produces a higher pitch at the fundamental frequency, a closed pipe or an open pipe? Why?
4. When you see a longitudinal wave, what is the relati ...[text shortened]... wer that the elevator is using?
10. Where is the best place to cook hotdogs with a solar oven?[/b]

1.Dang it, I got a B on my optics test. Um, A?
2.False, only true if closer to mirror than focal point.
3.Closed, shorter wavelength.
4.Parallel
5.A Node (Nodes have "no des": no displacement!)
6.True
7.B
8.Something with pressure, but I'm not sure.
9.Power is force times velocity from a derivation, so 600 N times 18 passengers times 9 meters per second equals 97,200 Watts.
10. Someplace with sun all year round, so the North Pole?😕

Originally posted by abejnood
1.Dang it, I got a B on my optics test. Um, A?
2.False, only true if closer to mirror than focal point.
3.Closed, shorter wavelength.
4.Parallel
5.A Node (Nodes have "no des": no displacement!)
6.True
7.B
8.Something with pressure, but I'm not sure.
9.Power is force times velocity from a derivation, so 600 N times 18 passengers times 9 meters per second equals 97,200 Watts.
10. Someplace with sun all year round, so the North Pole?😕

7.C - the horizontal force is frictional force. Well actually it is in the opposite direction of movement but while the rock is in the highest point of it's trajectory, the force vector is horizontal.

Eh, this test seems to be quite interesting but as my default language isn't English, I'm not quite used to these scientific terms. Anyway, I'll use the dictionary and try to get some more answers from my side if more questions are posted as the ones already posted are already answered.

Originally posted by abejnood
1.Dang it, I got a B on my optics test. Um, A?
2.False, only true if closer to mirror than focal point.
3.Closed, shorter wavelength.
4.Parallel
5.A Node (Nodes have "no des": no displacement!)
6.True
7.B
8.Something with pressure, but I'm not sure.
9.Power is force times velocity from a derivation, so 600 N times 18 passengers times 9 meters per second equals 97,200 Watts.
10. Someplace with sun all year round, so the North Pole?😕

I believe you missed 3 (or 4).

- I changed the last question, but you still missed it (the answer is equator, direct sunlight all year.)

- You mixed concave and convex mirrors.
- (kbauman, he is correct. At the top of the projectory, the rock only has gravity on it - a vertical force. Since it has no velocity, air resistance and friction are not factors.)
- 8 - No.
- 9 - No, wrong equation. No answer required, but give me the equation and fill it in appropriately.
- Need an answer for #10.

Originally posted by Ramned
[b]Harder!

1. When looking into a concave mirror, is the image you see
A) Virtual B) Real C) Possibly both, real or virtual.
2. True or False: Convex mirrors magnify the images.
3. What produces a higher pitch at the fundamental frequency, a closed pipe or an open pipe? Why?
4. When you see a longitudinal wave, what is the relati ...[text shortened]... ) questions I can think of! Appears that AThousandYoung has common sense / is a good physicist.[/b]

1) Well it's definitely real. I don't know what a "virtual image" is though. Since C) says "possibly" I'll go with C).

2) True

3) Don't know. I'd have to spend some time re-reading this material. I do remember that a closed end forces there to be a node at the end...right?

4) Energy doesn't have a direction associated with it I don't think so...no relation?

5) Node.

6) True.

7) C). Horizontally it's air resistance, vertically it's gravity. If we were in a vaccuum it would be B.

8) Clouds reflect light and heat back down to Earth. They act as a blanket.

9) Too lazy to work it out. I'd need to do a bit of review anyway I think.

10). Thickness, length and material?

ATY studied biochemistry in school and took a lot of physics classes along the way.

Originally posted by Ramned
I believe you missed 3 (or 4).

- I changed the last question, but you still missed it (the answer is equator, direct sunlight all year.)

- You mixed concave and convex mirrors.
- (kbauman, he is correct. At the top of the projectory, the rock only has gravity on it - a vertical force. Since it has no velocity, air resistance and friction are not facto ...[text shortened]... - No, wrong equation. No answer required, but give me the equation and fill it in appropriately.

The rock does indeed have velocity at the top of it's parabola since you threw it at 45 degrees. It has no VERTICAL velocity though.

Originally posted by Ramned
I believe you missed 3 (or 4).

- I changed the last question, but you still missed it (the answer is equator, direct sunlight all year.)

- You mixed concave and convex mirrors.
- (kbauman, he is correct. At the top of the projectory, the rock only has gravity on it - a vertical force. Since it has no velocity, air resistance and friction are not facto ...[text shortened]... swer required, but give me the equation and fill it in appropriately.
- Need an answer for #10.

The rock has a velocity at that point. It doesn't just stop moving, and then continue except if you threw it exactly upwards, but you stated that we throw it at a 45 degree angle.

EDIT: Eh, AThousandYoung was faster then me.

8. Clouds are seen when a cyclone is running the local weather controls. A cyclone brings us more humid weather (rain/snow), thus clouds, but an anti-cyclone brings clear sky and the temperature goes to higher extremes - hotter in summer, colder in winter. Also, the weather is less humid. I think this has nothing to do with the fact that it is night or day.

Originally posted by AThousandYoung
1) Well it's definitely real. I don't know what a "virtual image" is though. Since C) says "possibly" I'll go with C).

2) True

3) Don't know. I'd have to spend some time re-reading this material. I do remember that a closed end forces there to be a node at the end...right?

4) Energy doesn't have a direction associated with it I don't thin TY studied biochemistry in school and took a lot of physics classes along the way.

You missed about 5:

- #1-2 Mixed up concave vs convex (or guessed wrong) A virtual image is not an actual reflection - light creates the image. On number 1, explain why it is C 😉 (hint abejnood has already said why.)
- 3 - No.
- 4 - No. By Direction, I mean direction of the wave, not energy.
- 9 - Just tell the way you would figure that out.
- 10 - Length/Thickness/Material go together. One more variable.

Originally posted by Ramned
Good - #2 - it is a medium, not air necessarily, but you're right.

Explain why on #1.

What to explain? He showed all the way he got to the solution as well as the formula of Kinetic Energy.

EDIT: Where did those posts go?