How to find synthesis of data in physics

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ACT Science › How to find synthesis of data in physics

Questions 1 - 10
1

A student was interested in determining the relationship between the current, voltage, and resistance in a direct circuit, such as those exemplified by batteries connected to light bulbs. The student built the circuit presented in Figure 1 using a 2 ohm resistor.

Figure 1:

Vt_act_ps_4

The current that flows through the circuit can be calculated using the equation , where is the voltage of the battery, is the current flowing through the circuit, and is the resistance of the resistor.

The student used a 2 ohm resistor and batteries of various voltages to obtain the results in Table 1. The currents shown in the table are NOT calculated using the formula , but instead directly measured from the circuit using an ammeter. It is important to note that the measured current will only exactly equal the calculated current if the system contains no internal resistance.

Table_1

The passage and Table 1 present results with ideal batteries that do not have any internal resistance. If the batteries used were a real batteries that had internal resistance, how would the measured currents of the system change?

It would decrease.

It would increase.

It would remain the same.

It cannot be determined how current would change.

Explanation

If the batteries used in the circuit were to have additional resistance, then the overall resistance of the circuit would increase. Because we know that current and resistance are inversely related by or , we know that increasing resistance would decrease current (assuming voltage remains the same).

2

A company developed new prototype car and wanted to test the new car. The car's acceleration time from 0mph to 60mph and stopping time from 60mph to 0mph were measured. An obstacle course involving a lot of turns was also constructed to determine how well the car can handle turning. The main concern of the company is the safety of the car and therefore all of the tests were performed on dry concrete, concrete after simulated rain, concrete that was covered with snow and in sand.

Act 1

In order for the car to be safe on the roads, it is necessary for the car to have a stopping time of 4.5 seconds. What surfaces would the car not be safe on?

Rain and snow

All surfaces

Sand, snow and rain

Sand and rain

Explanation

The necessary stopping time is 4.5 seconds. When it comes to stopping time, the shorter the time the better for avoiding any hazards. Therefore the stopping times that are longer than 4.5 seconds are not safe. The rainy condition has a stopping time of 5.0 seconds and the snowy condition has a stopping time of 6.2 seconds. These two conditions are not safe when using this car.

3

Laura is performing an experiment with a 5kg weight tied to a 3m rope tied to the ceiling as shown:
Screen_shot_2013-11-03_at_8.09.39_pm

Laura drops the weight and allows it to swing freely. She measures how long it takes for the weight to return to it's original position (assume no forces outside of gravity are acting upon the pendulum). This is also called one oscillation.

Experiment 1:

Laura created the following table for her first measurement of the pendulum's oscillations.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 2:

Laura performed the experiment again, this time using a 6kg weight.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 3:

Laura performed the experiment again, this time using a 3kg weight and a 5m rope.Screen_shot_2013-11-04_at_8.30.58_am

If Laura recreated experiment 1 using a 10kg weight, how long would 2 oscillations last?

6.949

8.972

13.898

10.212

31.416

Explanation

As shown by comparing experiment 1 and 2, the actual mass of the weight has no effect upon how long each oscillation is.

4

Scientist 1: Scientist 1 believes that light displays particle behavior. This means that rays of light have their own associated momentum. Furthermore, Scientist 1 does not believe that light will exhibit wave behavior.

Scientist 2: Scientist 2 disagrees with Scientist 1 and believes that light can exhibit wave behavior, but does not display particle behavior. In other words, this scientist believes that light does not have any momentum.

Experiment: To settle their disagreement, the scientists setup the following experiment. The scientist take dark metallic material. This material is attached to pole and the metallic material can spin if it is subjected to a force; similar to a watermill or wind turbine. This setup is then placed outside and exposed to sunlight.

Assuming that sunlight displays particle behavior, what is the best way to design a device to absorb solar energy and turn it into electrical energy?

Cannot be determined from the given information

A flat solar panel facing the sun

Solar cells placed on the surface of a wind turbine

Solar cells placed in the shade, but with reflected sunlight aimed at the solar cells

Use solar cells placed underwater to collect refracted sunlight

Explanation

It is assumed that light exhibits particle behavior with momentum, but there is no information on how this affects the amount of sunlight absorbed. In addition, there is no information given on how to effectively build a device to absorb sunlight that can be converted into electrical energy so the answer cannot be determined.

5

Experiment 1

A scientist develops the following setup, shown in Figure 1 below, to study the charges of radioactive particles. A radioactive sample is placed into a lead box that has an open column such that the particles can only exit from one direction. A detector is placed in front of the opening. A metric ruler (centimeters (cm)), is aligned on the detector such that zero is directly in front of the opening of the column, with the positive values extending to the left and the negative values to the right. On the left side of the experimental setup, there is a device that generates a magnetic field that attracts positively charged particles and repels negatively charged particles.

Radioactivity_fig_1

Figure 1.

The device detects particles in three different places: alpha, α; beta, β; and gamma, γ; as labeled in Figure 1. The paths these particles take from the source of radioactivity are shown.

Experiment 2

A different scientist finds the following data, shown in Table 1, about the energies of the α, β, and γ particles by observing what kinds of materials through which the particles can pass. This scientist assumes that the ability of particles to pass through thicker and denser barriers is indicative of higher energy. Table 1 summarizes whether or not each type of particle was detected when each of the following barriers is placed between the radioactivity source and the detector. The paper and aluminum foil are both 1 millimeters thick, and the concrete wall is 1 meter thick.

Radioactivity_table_1

It is discovered that a certain element in the Earth's crust emits beta particles, and furthermore, that beta particles can cause cancer. Should architects building houses in the areas where this phenomenon is found in high abundance be mandated to build basements with concrete walls with a minimum thickness of one meter?

No, because beta particles are not energetic enough to pass through an aluminum foil sheet.

Yes, because there will be very large numbers of beta particles emitted from the Earth's crust in these areas.

Yes, because beta particles are only stopped by concrete walls at least one meter thick.

No, because beta particles are negatively charged, and thus will bounce off the basement's external walls.

Explanation

Table 1 shows that a simple sheet of aluminum foil can deflect beta particles. Thus, we know that any basement walls will be sufficient to deflect beta particles, and extra measures to build thick walls would be a waste of materials.

6

Laura is performing an experiment with a 5kg weight tied to a 3m rope tied to the ceiling as shown:
Screen_shot_2013-11-03_at_8.09.39_pm

Laura drops the weight and allows it to swing freely. She measures how long it takes for the weight to return to it's original position (assume no forces outside of gravity are acting upon the pendulum). This is also called one oscillation.

Experiment 1:

Laura created the following table for her first measurement of the pendulum's oscillations.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 2:

Laura performed the experiment again, this time using a 6kg weight.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 3:

Laura performed the experiment again, this time using a 3kg weight and a 5m rope.Screen_shot_2013-11-04_at_8.30.58_am

How long would 4 oscillations be, using the 3m rope and the 6kg weight?

13.896

12.566

2.565

53.828

Explanation

Based on experiment 2, each oscillation is approximately 3.474 seconds long. 4 oscillations would therefore last approximately 13.896 seconds

7

Laura is performing an experiment with a 5kg weight tied to a 3m rope tied to the ceiling as shown:
Screen_shot_2013-11-03_at_8.09.39_pm

Laura drops the weight and allows it to swing freely. She measures how long it takes for the weight to return to it's original position (assume no forces outside of gravity are acting upon the pendulum). This is also called one oscillation.

Experiment 1:

Laura created the following table for her first measurement of the pendulum's oscillations.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 2:

Laura performed the experiment again, this time using a 6kg weight.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 3:

Laura performed the experiment again, this time using a 3kg weight and a 5m rope.

Screen_shot_2013-11-04_at_8.30.58_am

Which of the following statements is a valid conclusion?

The length of time of each oscillation is directly related to the length of the rope

The length of time of each oscillation is inversely related to the length of the rope

The length of time of each oscillation is directly related to the mass of the weight

The length of time of each oscillation is inversely related to the mass of the weight

Explanation

In the experiment, the only variable that affects the amount of time of each oscillation is the length of the rope.

8

Laura is performing an experiment with a 5kg weight tied to a 3m rope tied to the ceiling as shown:
Screen_shot_2013-11-03_at_8.09.39_pm

Laura drops the weight and allows it to swing freely. She measures how long it takes for the weight to return to its original position (assume no forces outside of gravity are acting upon the pendulum). This is also called one oscillation.

Experiment 1:

Laura created the following table for her first measurement of the pendulum's oscillations.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 2:

Laura performed the experiment again, this time using a 6kg weight.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 3:

Laura performed the experiment again, this time using a 3kg weight and a 5m rope.

Screen_shot_2013-11-04_at_8.30.58_am

If Laura stopped experiment 3 after 10 seconds, how many oscillations would the pendulum have gone through?

2.23

3

2

2.5

Explanation

Since each oscillation lasts 4.486 seconds,

gives us the answer of 2.23 oscillations.

9

Laura is performing an experiment with a 5kg weight tied to a 3m rope tied to the ceiling as shown:
Screen_shot_2013-11-03_at_8.09.39_pm

Laura drops the weight and allows it to swing freely. She measures how long it takes for the weight to return to it's original position (assume no forces outside of gravity are acting upon the pendulum). This is also called one oscillation.

Experiment 1:

Laura created the following table for her first measurement of the pendulum's oscillations.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 2:

Laura performed the experiment again, this time using a 6kg weight.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 3:

Laura performed the experiment again, this time using a 3kg weight and a 5m rope.

Screen_shot_2013-11-04_at_8.30.58_am

How much longer does each oscillation in experiment 3 take in comparison to experiment 1?

1.012

3.14

1.111

0.682

Explanation

To compare how much longer each oscillation in experiment 3 is, simply subtract the two values.

10

Laura is performing an experiment with a 5kg weight tied to a 3m rope tied to the ceiling as shown:
Screen_shot_2013-11-03_at_8.09.39_pm

Laura drops the weight and allows it to swing freely. She measures how long it takes for the weight to return to it's original position (assume no forces outside of gravity are acting upon the pendulum). This is also called one oscillation.

Experiment 1:

Laura created the following table for her first measurement of the pendulum's oscillations.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 2:

Laura performed the experiment again, this time using a 6kg weight.

Screen_shot_2013-11-03_at_8.19.19_pm

Experiment 3:

Laura performed the experiment again, this time using a 3kg weight and a 5m rope.

Screen_shot_2013-11-04_at_8.30.58_am

If Laura recreated experiment 3 using a 5m rope and a 20kg weight, how long would 2 oscillations last?

8.972

35.888

2.243

6.729

Explanation

As shown by comparing experiments 1 and 2, the mass of the weight has no effect upon the time of each oscillation.

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