ACT Past Papers with Answers

Paper 59 · ACT April 2010 · Form 68G · Science Test

Suppose that a fourth group of pots containing Species B seedlings had been suspended at a water depth of 0.3 m. The ayeragc shoot length of these seedling,s in late September would most likely have been: 40 20 200 4￿ 600 800 dry tnass (mg) 60 40 20 200 400 600 800 dry rnass (mg)

Paper 59 · ACT April 2010 · Form 68G · Science Test

Ai the conclusion of Study 2, a seedling of Species B was found to have a dry mass of 400 mg and a shoot , length of 33 cm. Based on Figure 3, this seedling most likely had been submerged at which of the following water depths?

Paper 59 · ACT April 2010 · Form 68G · Science Test

Which of the following sets of data points most likely yielded the best-fit curve for surviving Species B seedlings grown at a depth of 0.4 m ? 60 £40 20 200 400 600 800 dry mass (mg) £40 20 200 400 600 800 dry mass (rllg) 60

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to the result8 of Studies l and 2, for a given water depth, how did surviving seedlings of Species A Collkpare to surviving seedlings of Species B ? On average, seedlings of Species A had: B, longer shoot lengths but lesser dry rnass. shorter ghoot lengths and lesser dry mass. shorter shoot lengths but greater dry ￿ass.

Paper 59 · ACT April 2010 · Form 68G · Science Test

Of the 8 Species A seedlings grown at a water depth of

Paper 59 · ACT April 2010 · Form 68G · Science Test

Which of the labeled colonies shown in FiguTe 2 did NOT form in the, absence of Leu ?

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to Table I, how many of Èhe strains tested in Experiment I were able to grow on the EPS that lacked histidine? 10 Note: + indicates colonies formed" _ indicates colonies did not fonn. ACT.88G 40 GO ON TO THE NEXT PAGE. 40000000004

Paper 59 · ACT April 2010 · Form 68G · Science Test

Which of the labeled colonies shown in Figure 2 is most likely to be fiorn Strain 4 ? B, Colony N

Paper 59 · ACT April 2010 · Form 68G · Science Test

Suppose cells from Strain 2 had been incubated on an EP lacking both His and Leu. Do the data in Table I indicats that colonies would have formed? Strain 2 can grow without both His and Leu. Strain 2 cannot grow without His. Strain 2 can grow without both His and Leu, Strain 2 cannot grow without Leu,

Paper 59 · ACT April 2010 · Form 68G · Science Test

Based on Table l and Figure 2, which mixed culture, if any, contained cells from Strains 6 and 10 ?

Paper 59 · ACT April 2010 · Form 68G · Science Test

Before beginning the experiments, the students steril- ized the velvet cloths used to transfer cells from the NAPS to the EPS. The most likely reason that the velvet cloths were stcrilized was to avoid contaminat- ing the; G, EPS WiLh cells that were not from the NAPS. velvet cloths with yeast from the NAPS. velvet cloths with bacteria from the NAPS. ACT-68G 41 GO ON TO THE EXT PAGE. 40000000004 Passage 111 When an asteroid hits ihe surface of a planet or moon, an impact crater ks formed. An ast6roid that hits Earth under .a specific set of conditions (including speed arid anglc), referred to here as Set C, forms a crater with a diameter about 20 times the asteroid's diameter. Figure I shows the energy released by the impact, for a range of asteioid diameters. 100,000,000 10,000,000 1,000,000 100,000 10,000 1,000 100 FiguÉe 2 shows the average amount of time that elapses between consecutive impacts on Earth by asteroids with the same diameter, for a range of asteroid diameters. Figure 3 shows the perc¢nt of the surface of the Moon, Mercury, and Mars that is covered by impact craters, for various ranges of crater diameier, 10 asteroid diameter (km) 1,000,000 500,000 Figure 2 100,000 50,000 Key oon 10,000 5,0 ercury Mars 1,000 100 50. 10 $ 0.2 (J irnp￿t crater diameter (km) asteroid diameter (km) Fioure 3 Note.. One energy unit - the energy released by the detonation of I million tons of TNT. Figures adapted from Eugene M, Shoemaker and Caiolyn S. Shoemaker, "The Role of Collislons. 1999 by Sky Publishing Corp. Fioure I Aryf.88G 42 GO ON TO THE NEXT 40000000004

Paper 59 · ACT April 2010 · Form 68G · Science Test

Suppose that 55 units of energy were released when a partkcular asteroid, under Set C conditions, hit Earth. According to Figure I, the asteroid's diameter was most likely closest to which of the following.

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to Figure 2, for progressively larger aster- olds, the aveTage amount of time that elapses between consecutive impacts on Earth by asteroids with the same diameter: increases only. G, decreases only. varies, but with no general trend. remains tlie same.

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to Figure 3, for any given range of crater diameters, the percent of the surface of Mars that is covered by iu]pact craters with those diameters is: the Moon. the Moon. ACT.68G 43 GO ON TOTHE NE TPA 40000000004 Passage IV A teacher placed 50 ML of Liquid A at 20°C in a buret (see Figure l). A buret is a graduated tube with a Jtopcock. Liquid flows out of the buret when the stopcock is opened. Table I gives the density, molecular mass (in atomic mass units, arnu), and tnolecular volume (in nm I billion nm - l Jn) for several liquids at 20°C. Table I buret Molecular tnass (amu) Molecula volume Density (g/mL) Liquid Acetone DMSO liquid Isopropanol Nonane Toluene stopcock Figure I The stopcock was opened and the flow time, the time it took for 20 ML of the liquid to flow out of the buret, was measured and found to be 7 sec. The Procedure was repeated with LiquÉd B, which had a flow time of 14 sec. The teacher asked 3 students to try to explain why the liquids had different flow times. SmdÉnt I Liquid B drained more slowly thall Liquid A because it is denser than Liquid A. As a liquid flows, some of its molecules bump into each other. This causes the molecules to lose speed kn the direction of fl'ow, slowing the overall flow of the liquid. Since molecules of a denser liquid are closer together than are molecules of a less deuse liquid, coLLisions occur more often in the denser liquid. Thus, if 2 liquids are at the sa￿e temperature, the less dense liquid will always flow more easily.

Paper 59 · ACT April 2010 · Form 68G · Science Test

Suppose an asteroid, under Set C conditions, hit Earth to form a crater 20 km in diameter. Based oll Figure I and other information provided, that asteroid impact mosi likely released an amount of enetrgy closest to which of the following. 1,000 energy units 3,000 energy unit8

Paper 59 · ACT April 2010 · Form 68G · Science Test

Assume that an asteroid that hit Earth 65 million years ago was 10 km in diameter, Also assume that another 10 km asteIoid will hit Earth in the future. If the amount of time th'at elapses between these consecutive impacts is equal to th6 averaoe amount of time as given by Figure 2, a 10 kn] diameter asteroid will next hit Earth approximately: 35 million years from now. 65 million years from now.

Paper 59 · ACT April 2010 · Form 68G · Science Test

In the teacher's demonstration, as the 7 sec ela during the measurement of Liquid A, the height o liquid in the buret: increased only. increased, then decreased.

Paper 59 · ACT April 2010 · Form 68G · Science Test

Based on Student I's cxplanation, which of the Ikquids listed in Table I would flow most easily at 20°C ? sed

Paper 59 · ACT April 2010 · Form 68G · Science Test

Suppose thal the teacher had also tested isopropanol in the demonstration and found Rt to have a flow time of I I sec. Student I Wollld claim that isopropanol.. is more dense than Liquid A, but not as dense as Liquid B. is more dense than Liquid B, but not as dense as Liquid A. smaller molecular mass than Liquid B. smaller molecular mass than Liquid A.

Paper 59 · ACT April 2010 · Form 68G · Science Test

Is the claim "At 20'C, nonane flows more easily thaA acetone" con8lStent WLth Student 2's explanation? than acetone. than acetone. than acetolle. vOlu￿e than acetonc. Student 2 Liquid B drained more slowly than Liquid A because it has a greater molecular mass (the mass of each mole- cule) than Liqllid A. Consider 2 objects o'f different mass. More force is required to move the object with the greater mass. Thus,.if 2 liquids are aL the same temperature,. Èhe liquid with the smaller molecular mass will always flow more easily. Student 3 Liquid B drained more slowly than Liquid A because it has a larger molecular volume (the Yolume occupied by each molecule) than Liquid A. Large molecules readily bU￿P into each other when a liquid flows, forming molecu- lar "logjams" that slow down the overall flow. Thus, if 2 liquids are at the same temperatUTe, the liquid with the smaller molecular volume will always flow more easily. THE NEXT P ACT.£8G 44 GOONT 000000000

Paper 59 · ACT April 2010 · Form 68G · Science Test

Which of the following graphs of the relative viscosi- ties of DMSO, H O, and isopropanol is most consistent with Student 3,8 explanation?

Paper 59 · ACT April 2010 · Form 68G · Science Test

Suppose that Liquid A had been isopropanol and Lxquid B had been nonane. The results of the teacher's demonstration wollld have supported the explana- tion(s) pi"ovided by which S￿dentIs)? P. Students 2 and 3 only '> 0,5 >0.5

Paper 59 · ACT April 2010 · Form 68G · Science Test

Consider the data for heptane (a liquid) at 20°C shown in the table below: Deusity Molecular mass Molecular volume >0.5 > 0.5

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to Figure 3, the lowest temperature at which bubbles will form in a 30fo EO solution at l atrn is closest to which of the following. 10

Paper 59 · ACT April 2010 · Form 68G · Science Test

At IOQC and l atrll, as fo EO increases from 0% to IOOfo, the mass per unit volume: increases only. increases, then decreases.

Paper 59 · ACT April 2010 · Form 68G · Science Test

At l atm, which of the followintr solutions WILI have the lowest tnelting point? 0 10 20 30 40 50 60 70 80 90 100 %EO Figure 2 46 GOONT E NEXT ACY-68G 40000000004

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to Figwes 2 and 3, at l atm, a solution of ethylene oxide in H O that has & bubble point of 15°C will have a freezing point closest to which of the following ,

Paper 59 · ACT April 2010 · Form 68G · Science Test

Based. on Figure 2, at l atm, which of the following solutions has a freezing point Closest to the freezing Polllt of pure H O ? ACT- 47 GOO THE EXT PAG 40000000004 Passage Vl In a rain Clo￿d, small particles called cloud condensa- tion nuclei (CCN) attract nearby water dioplets to form a cloud droplet. A cloud droplet grows by attracting more water droplets until it becomes a raindrop, which then falls from the cloud. Rainfall can be increased by seeding the cloud with additional small particles, such as Nacl paiti- cles, to act as CCN. Key Flare Type: Over a year, 2 studies of cloud-seeding were done at a subtropical location, using every cumulus cloud that was isolated from other clouds, Èhat had a top at an altitude between 3,350 m and 4,900 m, and that had a liquid water contellt of at least 0.5 g/m 10 100 1,000 10,000 seeding concentratioD (p&rticleslcm) Figure I Table 1 and Figure 1 adapted from Y. Segal et al., "Effects of hygrosoopic seeding on raindrop formation as seen from slrnula- tions using 8 2000-bin spectral cloud parcel model., 02004 by Elsevier B, V. Szudy 2 Radar was used to monitor how the tnass of raindrops within each cloud changed over the 55 minutes following the time the plane entered the base of the cloud. The aver- aged results for all the unseeded clouds and for all the seeded clouds are shown in Figure 2. StHdy I Four types of flares (A-D) were used. Flares of each e, when ignited, released Nacl particles having a spe- ic distribution of particle sizes (see Table l). iy ci Key unseeded clouds seeded clouds Table I 500 Percent of Nacl particles having diameters Flare Type

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to the resulls of Study I, as the seeding con- centration increased, the average amount of rainfall that reached the ground: increased for all 4 types of flare8. increased for Flare Types A and B, but decreased for Flare Trpes C and D. for Flare Types C and D,

Paper 59 · ACT April 2010 · Form 68G · Science Test

Based on the passage, whit is the correct ord¢r of rain- drops, water droplets, and cloud droplets according to their diamelers, from smallest to largest?

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to the results of Study 2, how did the rain- drops in the seeded clouds differ from the raindrops in the unseeded clouds with resp¢ct to their maximum Enass? clouds to reach a maximum mass, and they reached a greater maximum ￿ass. clouds to reach a maximum mass, and they reached a greater maximum mass. clouds to reach a maximum mass, and they rcached a lesser maximutn mass, clouds to reach a rAaximum mass, and they reached a lesser maximum rnass. ACT.e8G 49 GO ON TO THE NEXT P 40000000004 Passage Vll An RCL circuit contains an alternating current (AC) power supply, a resistoi having a resistance R, a capacitor having a capacitance C, and an inductor having an induc- tance L (see Figure l ). Figure 3 shows how (Oo varies with L and C. Key 10 C (10- farad) • 1.0 resistor AC power supply capacitor 10,0 induttor Figure I The capacitor and inductor each possess impedance, a type of electrical resistance. The angular freqLiency of the cur- reni, w, is a rneasuKe of the number of times each second that the current reverses direction.

Paper 59 · ACT April 2010 · Form 68G · Science Test

The design of Study I differed from the de8ign of Study 2 in thai in Study I, the: rainfall from a cloud was measured, whereas in Study 2, the particle-size distiibution in types of flares was determined, mass of raindrops in a cloud was determined, whereas in Study 2, the particle-size distribution in types of flaies was determÈned. rainfall from a cloud was measured, whereas in Study 2, the mass of raindrops in a cloud was determined. mass of raindrops in a cloud was deteTmined, whereas in Study 2, rainfall from a cloud was measured.

Paper 59 · ACT April 2010 · Form 68G · Science Test

Which of the following, statements gives the most likely reason that clouds with tops above an 21titllde of 4,900 m were not included in the studies? Above 4,900 m in such clouds, there would be present., only water vapor. ice crystals but few water droplets. water droplets but few ice crystals.

Paper 59 · ACT April 2010 · Form 68G · Science Test

Which of the following statements about the particle- size distribution in the 4 types of flares is supported by Table 17 belonged to the largest size category. belonged to the smallest size category. belonged to the largest size category, whereas for Flare Types C and D, the majority of particles belonged to the smallest S17e category. belonged to the SEnallest size category, whereas for FlaIe Types C and D, th¢ majorkly of particles beIonged to the largest size category,

Paper 59 · ACT April 2010 · Form 68G · Science Test

What LS the resonant angular fiequency of the RCL cir- cult for the conditions given in Figure 2 ?

Paper 59 · ACT April 2010 · Form 68G · Science Test

Accordin<y to Figure 3, for C - 1.0 x 10- farad, as L increases., o)0. increases only. varies, but with no general trend. remains the same. 0,95

Paper 59 · ACT April 2010 · Form 68G · Science Test

For the conditions specified in Figure2 and 30 ohms, the resistor will generate the greatest amount ol heat when O) is closest to which of the fol- lowing values? Figuie 2 Figure 2 adapted from David Halliday and Robert Resnick, Physles, Part 2, 3rd ed. @1978 by John Wlley and Sons, Inc. For a given R, the peak average current, I max? occurs at the résonant angularfreqL4ency, (J)0. ACT.68G 50 GOO TO THE NEXT PAGE.

Paper 59 · ACT April 2010 · Form 68G · Science Test

According to Figure 2, does o)0 vary with R ?

Paper 59 · ACT April 2010 · Form 68G · Science Test

For a given L, what LS the correct ranking of the values of C in Figure 3, frorn the C associated with the lowest Q)0 to the C associated with the highest (Oo io 10 10 io 10 10 io io io 10 10 10 END OF. TEST 4 STOPI DO NOT RETURN TO ANY OTHER TEST. ACT-68G 51 Forn] 68G (April 2010) Weimaraner Math Readin Science l) B