AAPT Exams 2000 Physics Olympiad Screen Exam (21-30)
 StudentCode Password Enter each group member's StudentCode and password and class period (1-8)

A converging lens has a focal length of 10 cm.   If an object is placed 50 cm from the lens, what will be the magnitude of the magnification of the image?

1/5
1/4
1/2
2
5

Viewed from one frame of reference, a 1500 kg automobile with a velocity of 25 m/s collides with a 1000 kg automobile at rest. The two automobiles stick together. What would be the velocity of the two cars immediately after the collision in a frame of reference moving at 10 rn/s in the same direction as the 1500 kg automobile?

25 m/s
15 m/s
5 m/s
0 m/s
-5 m/s

The most common isotope of Uranium, 23892U, radioactively decays into 20682Pb, Lead, by means of a series of alpha and beta particle emissions. How many of each particle must be emitted?

32 alphas and 10 betas
16 alphas and 16 betas
16 alphas and 8 betas
8 alphas and 6 betas
4 alphas and 16 betas

A small bird with a mass of 0.5 kg takes off from the ground and flies with an upward velocity of 3 m/sec for 10 seconds. Which of the following is closest to the minimum power that must be developed by the bird?

60 watts
15 watts
9 watts
6 watts
1.5 watts

Two iron spheres separated by some distance have a minute gravitational attraction, F. If the spheres are moved to one half their original separation and allowed to rust so that the mass of each sphere increases 41%, what would be the resulting gravitational force?

2F
4F
6F
8F
10F

After the switch in the accompanying circuit has been clossel for a very lorg time, what would be the total current in the circuit shown below?

0.53 amperes
0.90 amperes
1.5 amperes
1.9 amperes
2.0 amperes

Which of the following graphs would best represent the resistance versus temperature relationship for a superconductor?

A moving charged particle experiences no magnetic force Which of the following statements MUST be true?

The particle must be moving parallel to a magnetic field.
The particle must be moving perpendicular to a magnetic field.
The particle must NOT be moving in a magnetic field.
The particle must be moving in an electnc field.
None of the above must be true.

The NEXT two questions refer to the following situation. Three electric charges (Q1, Q2 & Q3) are arranged at three comers of a rectangle as shown in the diagram and each has a charge of -40 nC.

What is the magnitude of the net force on Q2?

1.4 x 10 -5 N
1.7 x 10 -5 N
4.2 x 10 -5 N
4.6 x 10 -5 N
14.7 x 10 -5 N

What would be the magnitude of the total electric field at center point X?

1440 N/C
720 N/C
360 N/C
180 N/C
90 N/C