A lidar (laser radar) gun is an alternative to the standard radar gun that uses the Doppler effect to catch speeders. A lidar gun uses an infrared laser and emits a precisely times series of pulses of infrared electromagnetic waves. The time for each pulse to travel to the speeding vehicle and return to the gun is measured. In one situation a lidar gun in a stationary police car observes a difference of 1.23 10-7 s in round-trip times for two pulses that are emitted 0.440 s apart. Assuming that the speeding vehicle is approaching the police car essentially head-on, determine the speed of the vehicle.

By what factor must your blood pressure increase to compensate for a 4 % narrowing in your blood vessels? (The pressure difference across your blood vessels is essentially equal to your blood pressure.) I am learning the bernoullis equation and also the poiseuille law. But can't figure out how to do this with only knowing a percent. I need each step please.

The very long cylindrical solenoid of (Figure 1) has a radius of 0.50 m and 1000 windings per meter along its length. A circular conducting loop of radius 1.0 m encircles the solenoid, with the long central axis of the solenoid passing through the center of the loop, and with the area vector of the loop parallel to the solenoid axis. The solenoid initially carries a steady current I, but the current is then reduced to zero during a 0.100-s time interval.

Part A

If the average emf induced in the loop during that interval is 0.80 V , what was the initial current magnitude?

An electron is constrained to the central perpendicular axis of a ring of charge of radius 2.3 m and charge 0.020 mC. Suppose the electron is released from rest a distance 0.056 m from the ring center. It then oscillates through the ring center. Calculate its period. (The electron is always much closer to the ring center than a radius.)

A piston-cylinder device contains 0.5 m³ air at 100 kPa and 1000 K. Because the outside is cooler (at 300 K), the hot air starts losing heat to the surroundings and the volume of air starts decreasing. Over a certain period of time the volume is observed to shrink by 50%.

The final temperature is lower or higher?

Determine the boundary work transfer (absolute value). in KJ

Two capacitors C₁ = 4.6 ?F, C₂ = 18.6 ?F are charged individually to V₁ = 15.3 V, V₂ = 4.4 V. The two capacitors are then connected together in parallel with the positive plates together and the negative plates together.
Calculate the final potential difference across the plates of the capacitors once they are connected.

Calculate the amount of charge (absolute value) that flows from one capacitor to the other when the capacitors are connected together.

By how much (absolute value) is the total stored energy reduced when the two capacitors are connected?

I am wondering whether the five1 units of the natural unit system really is dictated by nature, or invented to satisfy the limited mind of man? Is the number of linearly independent units a property of the nature, or can we use any number we like? If it truly is a property of nature, what is the number? -five? can we prove that there not is more?

In the answers please do not consider cgs units, as extensions really is needed to cover all phenomenon. - or atomic units where units only disappear out of convenience. - or SI units where e.g. the mole for substance amount is just as crazy as say some invented unit to measure amount of money.

Sound source A is located at x = 0, y = 0, and sound source B is located at x = 0, y = 2.0 m. The two sources radiate coherently and in phase. An observer at x = 15.8 m, y = 0 notes that as he takes a few steps from y = 0 in either the +yor −y-direction, the sound intensity diminishes. What is the lowest frequency, and the next to the lowest frequency of the sources that can account for that observation? (Enter your answers from smallest to largest.)

kHz

kHz

a) What are the different types of “light” (electromagnetic waves), starting from radio waves? Why do you think we can only see such a small portion of the electromagnetic spectrum? Why don’t we see X-rays or microwaves?

b) Explain what a photon is and what property of photons relates to different colors of light.

c) What is the frequency of light that has a wavelength of 400 nm? What is the color of such light? What is the energy of a photon of such light (in eVunits)?

A 1.8-cm-tall object is 28cm  to the left of a lens with a focal length of 14cm . A second lens with a focal length of -6cm  is 39cm  to the right of the first lens.

Part A:

Calculate the distance between the image and the second lens.

Part B:

Calculate the image height.

Please show how you obtained the answers!

If everyone living on Earth moved to the equator, the length of day would change. Calculate the change in the day length. (professor gave the hint to use r=R_E*cosΘ)

I know it has to do with conservation of momentum (L_i=L_f) and that the day will lengthen by less than a second, but I'm not sure how to estimate the inertia of people living around the world like normal unless I use the moment of inertia for a thin shell (2/3mr²) and I don't know where the equation above is supposed to be used....or what theta he is talking about.

An object with total mass m_total = 6.3 kg is sitting at rest when it explodes into two pieces. The two pieces, after the explosion, have masses of m and 3m. During the explosion, the pieces are given a total energy of E = 44 J.

1)What is the speed of the smaller piece after the collision? (m/s)

2)What is the speed of the larger piece after the collision? (m/s)

3)If the explosion lasted for a time t = 0.028 s, what was the average force on the larger piece? (N)

4)What is the magnitude of the change in momentum of the smaller piece? (kg-m/s)

5)What is the magnitude of the velocity of the center of mass of the pieces after the collision? (m/s)

• Draw a diagram including your chosen coordinate system.

• Label all quantities in the diagram using standard notation.

• List the known and unknown quantities. Circle the unknowns.

• Identify the equation you are using and show all your work. • At the end of each problem, check your answer. Do the units match? Is the answer reasonable? Does the plus or minus sign make sense?

3. In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straightaway at 71.5 m/s. The driver of the Thunderbird realizes that she must make a pit stop, and she smoothly slows to a stop over a distance of 250 m. She spends 5.00 s in the pit and then accelerates out, reaching her previous speed of 71.5 m/s after a distance of 350 m. At this point, how far has the Thunderbird fallen behind the Mercedes Benz, which has continued at a constant speed?

The numerical aperture of an instrument is 0.969. How far apart are the lines on a certain shell if they are just barely resolved when viewed with green light (548 nm)?