ACT Science Practice Test - 1 - online test

Energy travels through space by electromagnetic radiation (Table 1). There are many forms of radiant energy, such as sunlight, microwave oven energy, X?rays and heat from a fireplace. All forms of electromagnetic radiation exhibit wavelike behaviour and travel at the speed of light (c) in a vacuum. Wavelength, frequency and speed are the three primary characteristics of waves. Wavelength (λ) is the distance between two consecutive peaks in a wave. Frequency (ν) is the number of waves (cycles) per second that pass a given point in space. There is an inverse relationship between wavelength and frequency—short wavelength radiation has a high frequency, whereas long wavelength radiation has a low frequency.

Science lesson Science Practice Test 1 exam questions 1. question pragraph

Alfred and Gwen ran experiments to measure the wavelengths of various types of energy sources. Alfred used energy sources that emit microwave radiation, whereas Gwen used sources that emit infrared radiation. After determining the wavelengths of the energy sources used, they calculated the frequency of radiation for each source using the following formula for the speed of light:

- c = λν, where
- λ = wavelength (meters (m))
- ν = frequency (cycles per second = 1/s = Hertz (Hz))
- c = speed of light (m/s) = 2.9979 x 108 m/s

Frequency can be calculated by rearranging this equation to solve for frequency, ν = c/λ. Alfred and Gwen plotted frequency as a function of wavelength and the resulting graphs are shown in Figures 1 and 2.

Science lesson Science Practice Test 1 exam questions 1. question pragraph

Mercury lamps emit ultraviolet radiation. What is the wavelength of these ultraviolet rays?
Note: On both attached graphs, the x-axis should be labeled “wavelength” and the y-axis should be labeled “Hz”.

1 x 10-4 m

1 x 10-8 m

1 x 10-2 m

1 x 10-10 m

See Table 1. Ultraviolet radiation has a wavelength of 1 x 10-8 m.

Which graph depicts the relationship between wavelength and frequency?
Note: On both graphs in the attached “document,” the x-axis should be labeled “wavelength” and the y-axis should be labeled “Hz”.

Science lesson Science Practice Test - 1 exam questions 2 question 1 Answer

Science lesson Science Practice Test - 1 exam questions 2 question 2 Answer

Science lesson Science Practice Test - 1 exam questions 2 question 3 Answer

Science lesson Science Practice Test - 1 exam questions 2 question 4 Answer

This is the only graph that shows an inverse relationship. The longer the wavelength, the shorter the frequency.

The data points in Figure 1 appear in a decreasing pattern from left to right. If the axes of Figure 1 were to be switched, in other words with wavelength on the vertical axis (y-axis) and frequency on the horizontal axis (x-axis), would the points on the graph occur in a similar descending order?
Note: On both attached graphs, the x-axis should be labeled “wavelength” and the y-axis should be labeled “Hz”.

A trend line would have to be drawn on the graph to determine this answer.

Yes, the points on the graph would occur in a similar descending order.

The data points do not appear in descending order.

No, the points on the graph would not occur in a similar descending order.

The relationship between frequency and wavelength is inverse (mentioned in the question description), i.e., the longer the wavelength, the shorter the frequency.

One of the energy sources that Gwen used in her experiment was a dust cloud, as it emits infrared radiation. The radiation emitted from the dust cloud had a frequency of 0.000075 Hz. According to Figure 2, what was the wavelength of the infrared radiation?
Note: On both attached graphs, the x-axis should be labeled “wavelength” and the y-axis should be labeled “Hz”.

0.0003 m

0.0006 m

0.0004 m

0.0007 m

In Figure 2, the horizontal axis represents the wavelength and the vertical axis represents the frequency in Hertz. Locate the given Hz value on the y-axis, and coordinate the corresponding point with the value along the x-axis. The given frequency corresponds with 0.0004 meters.

Science lesson Science Practice Test - 1 exam questions 5 questionOne of the energy sources used in Alfred’s experiment was a television, as it emits microwave radiation. The radiation emitted from the television had a wavelength of 0.05 m. What was the frequency of the microwave radiation according to the attached graphic?

4 GHz

15 GHz

30 GHz

6 GHz

Look at the attached image. The 3rd point on the graph has a wavelength of 0.05 m and a frequency of 6 GHz.

Male and female gold claw fiddler crabs are invertebrates that inhabit sea beaches, brackish intertidal mud flats, lagoons and swamps. They have a hardened body shell called a carapace and two claws called chelpids. In females, the chelipeds are both small, whereas in males, one cheliped is larger than the other. The larger cheliped in the males is used for territorial displays, fighting other males and attracting females, whereas the smaller cheliped is used for eating and scavenging for food. After a fight between two males, the female usually chooses the victor as her mate. Variability in size may be what allows a female to choose the best mate and may relate to fighting ability and ultimately reproductive success.

In the wild, each male crab has a burrow, which it defends against intruders and which provides shelter for the crab. Males rarely fight females for burrows; instead, wandering males fight resident males in order to acquire their burrows. Claws can sometimes be lost during combat, which may affect male reproductive success. Although they do regenerate lost claws, the males have to allot more time and energy into claw regeneration than into actively courting females, which in turn can result in lower production of offspring.

Samira and Donovan, two behavioural ecologists were interested in examining size differences among males and females and length of combat bouts between males. For the first experiment, they measured claw and body length and width. For the second experiment they staged combats, in experimental terrariums, between residents and intruders. Donovan measured the females and Samira measured the males before allowing the males to fight.

Which conclusion can you draw from Table 3?

The larger the difference in claw length, the longer the combat duration.

The smaller the difference in claw length, the shorter the combat duration.

Male crabs, with medium-sized differences in claw length, battle for the longest time.

The more the crabs are evenly matched in size, the longer the combat duration.

In Table 3, under “none” (no size difference in claw length), the mean time is the longest of all the times shown.

Comparing males and females, which data show greater variability?

female cheliped and carapace size

male cheliped and carapace sizes

female carapace size only

male cheliped size only

See Figures 1 (females) and 2 (males) or, if you don’t know that greater spread of data points (along the X or Y axis) on a graph means greater variability, see Tables 1 and 2. Male cheliped width ranges from 4 mm to 8 mm, length from 8 mm to 21 mm; and carapace width ranges from 9 mm to 16 mm, length from 7 mm to 12 mm. For females, cheliped width is around 1.5 mm to 2 mm and length from 3.5 mm to 6 mm; and carapace width ranges from 9 mm to 13 mm and length from 7 mm to 10 mm.

For male fiddler crabs, which shows greater variability in length, the cheliped size or the carapace size?

Cheliped length shows greater variability.

Neither cheliped nor carapace size varies.

Cheliped and carapace length have the same variability.

Carapace length shows greater variability.

See Figure 2: The data points are stretched further apart along the vertical axis (length) for cheliped size than for carapace size. Or see Table 2: Cheliped length ranges from 8mm to 21 mm, whereas carapace length ranges from 7 mm to 12 mm.

Which number correctly finishes this sentence?
Male crabs, with a size difference of 6–10 mm in claw length, fought with each other for an average of _____ seconds.

48.9

19.6

30.4

12

See Table 3 and read the sentence under the table title. Large size differences (6–10 mm) in male claw length resulted in a mean combat duration of 19.6 seconds.

For female fiddler crabs, which shows greater variability in width, the cheliped size or the carapace size?

The cheliped width and carapace width have the same variability.

The cheliped size shows greater variability.

The carapace size shows greater variability.

Neither the cheliped size nor the carapace size varies.

See Figure 1: The data points are stretched further apart along the horizontal axis (width) for carapace size than for cheliped size. Or See Table 1: Cheliped width is around 1.5 mm to 2 mm, whereas carapace width ranges from 9 mm to 13 mm.