Sounds waves are disturbances in air molecules that move at 343 m/s. Pitch is a measure of a sounds frequency. A middle C note in music has a frequency (pitch) of 261.6 Hz.

a. If you are listening to a middle C, how many pulses (wave crests) of
sound hit you in one minute (1 minute is exactly 60 seconds)?
b. How far apart is each wave crest (wavelength) in a middle C note?
c. If that note was sung louder, would either the wavelength or
frequency change?

The air pressure in a tire sitting outside is 30 psi on a nice fall day when the temperature is about 80 F. (Assuming that the density of the air inside the tire does not change with temperature and that the air may be treated as an ideal gas), what would the tire pressure be:

A) At 32 F?

B) At 100 F?

If the recommended tire pressure is between 28 and 32 psi, do you need to do anything in either case above? If so, which and what?

1.) What do you observe about the equipotential lines very near the charges and very far away from them? How does a second charge affect the potential field of the first one?

You dive straight down into a pool of water. You hit the water with a speed of 5.0 m/s , and your mass is 70 kg.

Assuming a drag force of the form FDFD = (−1.50×10⁴ kg/s )v, how long does it take you to reach 2% of your original speed? (Ignore any effects of buoyancy.)

Two identical objects, A and B, are thermally and mechanically isolated from the rest of the world. Their initial temperatures are TA > TB. Each object has heat capacity C (the same for both objects) which is independent of temperature. (a) Suppose the objects are placed in thermal contact and allowed to come to thermal equilibrium. What is their final temperature? How much entropy is created in this process? How much work is done on the outside world in this process? (b) Instead, suppose objects A (temperature TA) and B (temperature TB < TA) are used as the high and low temperature heat reservoirs of a heat engine. The engine extracts energy from object A (lowering its temperature), does work on the outside world, and dumps waste heat to object B (raising its temperature). When the temperatures of A and B are the same, the heat engine is in the same state as it started and the process is finished. Suppose this heat engine is the most efficient heat engine possible. In other words, it performs the maximum work possible. What is the final temperature of the objects? How much entropy is created in this process? How much work is done on the outside world in this process?

A block of mass m = 2.1 kg slides down a 36 ° inclined ramp that has a height h = 3.1 m. At the bottom, it hits a block of mass M = 7.1 kg that is at rest on a horizontal surface. Assume a smooth transition at the bottom of the ramp. If the collision is elastic and friction can be ignored, determine the distance the mass m will travel up the ramp after the collision.

The figures show a hypothetical planetary system at two different times. The system has a star S and three planets, labeled A, B, and C. The table provides the mass of each body in the system, as well as their spatial coordinates (?,?) in their initial and final positions. The spatial coordinates of the bodies are given in Astronomical Units (AU). Body Mass (kg) Initital Position Final Position S ?S=2.0197×1030 (0,0) (?S,?S) A ?A=2.0735×1028 (0.3429,0) (0,−0.5335) B ?B=6.6485×1026 (0.5617,1.2553) (−1.5385,0) C ?C=8.4729×1027 (0,1.6711) (−0.8021,−0.6035) The initial velocity of the center of mass of the system is zero. Find the magnitude ?S of the star's displacement from the origin in its final position. An x y coordinate system. The star S is at the origin. Planet A lies on the positive x-axis. Planet B is in the first quadrant of the graph. Planet C lies on the positive y-axis. Initial Position An x y coordinate system. The star S is near the origin in the first quadrant. Planet A lies on the negative y axis. Planet B lies on the negative x axis. Planet C is in the third quadrant of the graph. Final Position ?S= AU

an optical system consists of an optical lens and a concave mirror, the focal length of length is f=20​cm, the distance between objective and lens is 30, the distance between lens and concave mirro is alos 30cm, the radius of concave mirror is 30cm.
​(a) find the location of the final image
​(b)is this a real or virtual image?
​(c)is this an erect or inverted image?
​(d)what is the overall transversal magnification?

A.) Sunlight strikes a piece of crown glass at an angle of incidence of 31.5deg. Calculate the difference in the angle of refraction between a yellow (580 nm) and a violet (410 nm) ray within the glass. The index of refraction is n=1.523 for yellow and n=1.538 for violet light. You have to calculate the angle of refraction for both light rays (they have different indices of refraction). You are looking for the difference of these angles.

B.) The ray now travels inside the glass. What is the minimum angle of incidence at which the yellow ray can hit the surface of the glass and become there totally internally reflected and not refracted? The angle of incidence is the angle with respect to the normal. Now the beam comes from inside and wants to leave the medium. Since the index of refraction of the medium is larger than 1 (index of refraction of air) there is a critical angle at which the beam is totally internally reflected.

1. In the lab, a student has created an oscillator by hanging a weight from a spring. The student releases the oscillator from rest and uses a sensor and computer to find the equation of motion for the oscillator: x(t) = 0.13m cos (6.3 ?????? t + 0.14 radians)The student ? then replaces the weight with a weight whose mass, m is twice as large as that of the original weight. The student again releases the weight from rest from the same displacement from equilibrium. What would the new equation of motion be for the oscillator?

2. Show that if one sound is twice as intense as another, it has a sound level of about 3 dB higher.

A bicycle racer sprints at the end of a race to clinch a victory. The racer has an initial velocity of 11.0 m/s and accelerates at the rate of 0.350 m/s2 for 7.00 s.

(a) What is his final velocity (in m/s)? 13.45 Correct: Your answer is correct. m/s

(b) The racer continues at this velocity to the finish line. If he was 300 m from the finish line when he started to accelerate, how much time (in s) did he save?

(c) One other racer was 5.00 m ahead when the winner started to accelerate, but he was unable to accelerate and traveled at 11.4 m/s until the finish line. How far ahead of him (in meters and in seconds) did the winner finish?

Bobsleds racing down a bobsled run often suffer glancing collisions

with the vertical walls enclosing the run. Suppose that a

bobsled of 600 kg traveling at 120 km h approaches a wall at

an angle of 3.0 and bounces off at the same angle. Subsequent

inspection of the wall shows that the side of the bobsled made

a scratch mark of length 2.5 m along the wall. From these

data, calculate the time interval the bobsled was in contact

with the wall, and calculate the average magnitude of the force

that acted on the side of the bobsled during the collision.

Determine which of the following observations are testable. For those that are testable:

• Determine if the observation is qualitative or quantitative.

• Write a hypothesis and a null hypothesis.

• What would be your experimental approach?

• What are the dependent and independent variables?

• What are your controls - both positive and negative?

• How will you collect your data?

• How will you present your data (e.g., chart, graph)?

• How will you analyze your data?

OBSERVATIONS

1. A plant grows three inches faster per day when placed on a windowsill than it does when placed on a on a coffee table in the middle of the living room.

2. The teller at the bank with brown hair and brown eyes is taller than the other tellers.

3. When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she does not exercise and eats fatty foods.

4. The Italian restaurant across the street closes at 9 pm but the one two blocks away closes at 10 pm.

5. For the past two days, the clouds have come out at 3 pm and it has started raining at 3:15 pm.

6. George did not sleep at all the night following the start of daylight savings.

A railroad car moving at a speed of 3.20 m/s overtakes, collides, and couples with two coupled railroad cars moving in the same direction at 1.20 m/s. All cars have a mass of mass 1.10 105 kg. Determine the following.

(a) speed of the three coupled cars after the collision____ (Give your answer to at least two decimal places.) m/s

(b) kinetic energy lost in the collision ___ J

2. A cue ball at rest on a frictionless pool table is hit dead center by a pool stick, giving it an impulse of +0.55 N · s. The ball slides (the combination of hitting the ball dead center and no friction allows this to happen) along the table and makes a head-on elastic collision with another pool ball. If both pool balls have a mass of 0.166 kg, determine the velocity of the second ball the instant after the collision. (Indicate the direction with the sign of your answer.) m/s

A vacuum tube diode consists of concentric cylindrical electrodes, the negative cathode and the positive anode. Because of the accumulation of charge near the cathode, the electric potential between the electrodes is not a linear function of the position, even with planar geometry, but is given by V(x)=Cx4/3 where x is the distance from the cathode and C is a constant, characteristic of a particular diode and operating conditions. Assume that the distance between the cathode and anode is 14.0 mm and the potential difference between electrodes is 200 V

Determine the value of C

Obtain a formula for the electric field between the electrodes as a function of x.

Determine the magnitude of the force on an electron when the electron is halfway between the electrodes

Determine the direction of the force on an electron when the electron is halfway between the electrodes