The graph below depicts the position of three different cars over a 15-second time interval.

At the point where all three cars meet, which car is traveling the fastest?

The graph below depicts the position of three different cars over a 15-second time interval.

What is the speed of Car 1 at time = 7s?

The graph below depicts the position of three different cars over a 15-second time interval.

如果车3以它目前的速度继续旅行at t = 15 seconds, what will it's position be at time = 20s?

A physicist wishes to study the trajectory of a ball launched horizontally. She varies parameters such as the launching velocity, starting height, and mass of the ball. For each trajectory, she records the time of flight (in seconds) and horizontal displacement (in meters). She assumes air resistance is negligible.

Figure 1

Using all of the data she collects, she constructs the following table:

Table 1

In Trial 1, if a fourth data point were collected in which the ball was thrown with a launching velocity of 40 m/s, what would be the approximate horizontal displacement in meters?

A physicist wishes to study the trajectory of a ball launched horizontally. She varies parameters such as the launching velocity, starting height, and mass of the ball. For each trajectory, she records the time of flight (in seconds) and horizontal displacement (in meters). She assumes air resistance is negligible.

Figure 1

Using all of the data she collects, she constructs the following table:

Table 1

If all of trial 3 were redone with a launching velocity of 20 m/s instead of 10 m/s, then compared to the data for trial 3 presented in the table, the horizontal displacement for all data points would be which of the following?

Experiment 1

一个科学家开发以下设置,所示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.

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

不同的科学家发现以下数据,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.

Based on Experiment 1, which of the following particles must be positively charged?

The period of a simple pendulumis defined as the amount of time that it takes for a pendulum to swing from one end to the other and back. In studying the period of a simple pendulum, two students express their opinions.

Student 1: The period of a pendulum depends on two factors: the mass of the pendulum's bob (the object swinging at the end of the pendulum) and the length of the pendulum. The height at which the pendulum is originally dropped does not affect the period.

Student 2: The period of a pendulumonly depends on the length of the pendulum. Varying the mass and the height at which the pendulum is originally dropped does not affect how long the pendulum takes to swing across.

The two students ran a series of trials to measure the period of a simple pendulum using varying weights and lengths. The students did not measure height as a factor. The results of the trials can be seen in the table below:

According to the data provided, what would we predict would happen if an experiment compared the periods of a pendulum made of a lead weight on a meter-long cord and a pendulum made of a tennis ball on a three-meter-long cord?

A scientist is testing the efficiency of a regular heat engine. A heat engine functions in the following manner: a chamber of gas is heated, increasing its pressure, which then causes the gas to expand to relieve some of that pressure. Next, the gas chamber cools off slightly, causing the pressure to decrease once again. This propagates the gas to compress slightly. Simply stated, this process produces mechanical work as the gas's expansion and contraction causes movement. A graph of the heat engine's pressure and volume is represented below, the letters A through D representing steps in the engine's repeating cycle.

Mechanical work for a gas process (movement from one pressure-volume state to another) is calculated using the formula, whererepresents work,represents pressure (which may or may not be constant), andrepresents a change in volume.

According to the equation, in which of the processes in the pressure-volume diagram was?

A scientist is testing the efficiency of a regular heat engine. A heat engine functions in the following manner: a chamber of gas is heated, increasing its pressure, which then causes the gas to expand to relieve some of that pressure. Next, the gas chamber cools off slightly, causing the pressure to decrease once again. This propagates the gas to compress slightly. Simply stated, this process produces mechanical work as the gas's expansion and contraction causes movement. A graph of the heat engine's pressure and volume is represented below, the letters A through D representing steps in the engine's repeating cycle.

Mechanical work for a gas process (movement from one pressure-volume state to another) is calculated using the formula, whererepresents work,represents pressure (which may or may not be constant), andrepresents a change in volume.

A gas process is considered isobaric if the pressure is held constant throughout the process. Which processes involved in the heat engine cycle described above can be considered isobaric?

A scientist is testing the efficiency of a regular heat engine. A heat engine functions in the following manner: a chamber of gas is heated, increasing its pressure, which then causes the gas to expand to relieve some of that pressure. Next, the gas chamber cools off slightly, causing the pressure to decrease once again. This propagates the gas to compress slightly. Simply stated, this process produces mechanical work as the gas's expansion and contraction causes movement. A graph of the heat engine's pressure and volume is represented below, the letters A through D representing steps in the engine's repeating cycle.

Mechanical work for a gas process (movement from one pressure-volume state to another) is calculated using the formula, whererepresents work,represents pressure (which may or may not be constant), andrepresents a change in volume.

A gas process is considered isochoric if the volume is held constant throughout the process. Which of the gas processes shown above can be considered isochoric?