ACT science practice test 44

Directions: Each passage is followed by several questions. After reading a passage, choose the best answer to each question and fill in the corresponding oval on your answer document. You may refer to the passages as often as necessary.

You are NOT permitted to use a calculator on this test.


A group of students gathered data to determine the factors that affect the speed of a wave pulse as it travels down a spring. They studied springs with their coils stretched out (high tension) against springs with looser coils (low tension) to determine how changing the characteristics of the medium affect wave speed. They also studied the effect of wave amplitude on the speed of the wave. Amplitude is the size of the disturbance.

The students conducted slow-motion video analysis of a wave pulse traveling down the spring and graphed the total distance the pulse traveled versus the total travel time, as shown in Figure 7.3.

Figure 7.3

Source: U.S. Geological Survey and www.thinkquest.org. http://earthquake.usgs.gov/learn/glossary/?term=amplitude.

1. To properly determine the effect of wave amplitude on wave speed, the students must:

A. make the spring tighter as they change the amplitude.
B. keep the tension the same but change the amplitude.
C. keep the amplitude and tension the same.
D. change both the tension and the amplitude.

2. According to Figure 7.3, the average speed of the high-tension/high-amplitude wave is closest in value to:

A. 0.50 m/s.
B. 0.72 m/s.
C. 0.91 m/s.
D. 1.10 m/s.

3. According to Figure 7.3, the low-tension/low-amplitude wave:

A. gained speed with time.
B. lost speed with time.
C. maintained a constant speed.
D. accelerated at first and then slowed down.

4. According to Figure 7.3, what is the effect of the tension of the spring on wave speed?

A. An increase in tension results in a greater wave speed.
B. An increase in tension results in a smaller wave speed.
C. Tension has no significant effect on wave speed.
D. Tension increases the amplitude of the wave.

5. What is the effect of amplitude on wave speed?

A. An increase in amplitude results in a greater wave speed.
B. An increase in amplitude results in a smaller wave speed.
C. Amplitude has no significant effect on wave speed.
D. Amplitude increases the tension of the wave.

6. Because sound behaves like a wave, one can infer from the results in Figure 7.3 that loud sounds:

A. travel at the same speed as soft sounds.
B. travel faster than soft sounds.
C. gain speed as they move through the air.
D. lose speed as they move through the air.

7. It is believed that light has the same characteristics as waves. From the results in Figure 7.3, one can infer that:

A. the speed of light depends on the characteristics of the material it goes through.
B. the speed of light depends on the brightness of the light.
C. light loses speed as it moves away from its source.
D. increased light frequency increases wave speed.

8. Water waves behave like spring waves in many ways. From the results in Figure 7.3, one can conclude that a water wave:

A. gains speed as it travels.
B. loses speed as it travels.
C. gains speed at first before slowing down to rest.
D. maintains a constant speed as it travels.

9. Assuming the low-tension/low-amplitude wave was able to keep moving, what is the approximate distance it would travel in 6.0 seconds?

A. 0.77 m
B. 1.6 m
C. 4.8 m
D. 6.4 m

10. In another experiment with springs, a large wave travels 10.2 m along a spring in 5.3 seconds. Approximately how much time would it take a small ripple to travel the same distance?

A. 1.9 seconds
B. 4.9 seconds
C. 5.3 seconds
D. 10.2 seconds