5. (5)

(a) Describe the de Broglie Model (also known as the de Broglie-Bohr Model) of the hydrogen atom.

(b) What was its motivation? (To address what problem was it proposed?)

(c) What drawbacks did it still have when it was proposed?

A motor with an internal resistance of R(motor) = 50 Ohms requires a potential difference of V(motor)=20V to work properly. As you don't have a 20V power source, you place two 12V batteries in series with a custom-built resistor with resistance R1.
(a) How much current moves through the motor when it is working properly?
(b) What must be the resistance of your custom-built resistor so that the potential difference across the motor is 20V?
(c) If you built your resistor from aluminium wire with diameter of 0.03mm and a resisticity of 2.65*10^-8 Ohmes meter, what length of wire must you use to create the necessary resistance of R1?
(d) What is the ratio of the power used by the motor to the power dissipated by the resistor, P(motor)/P(R1)?

What force, applied tangentially to the Earth along 45° of latitude in the direction of rotation for 1 day would result in a new day length that is shorter by 5.2 seconds? The Earth has mass 5.98x1024kg and radius 6380 km. Answer:

A 3 kg object is moving along the +y+y direction with a speed of 4 m/s when it experiences an impulse of 5i^−8j^5i^−8j^ Ns. What is the object's speed after the impulse is applied?

list at least two weaknesses of using sound to image an object. can these weaknesses be overcome, how?

0-9. GREENHOUSE EFFECT
CO2 passes short wave length light (visible) but blocks long wave length
radiation (IR). Explain how adding CO2 to an atmosphere increases the
surface temperature of a planet. Consider the temperature of the sources
of radiation in and out.

Show that angular momentum is conserved for a force law F = kr and find the allowed orbits.

When light with a wavelength of 215 nm is incident on a certain metal surface, electrons are ejected with a maximum kinetic energy of 3.33 × 10 − 19 J. Determine the wavelength of light that should be used to quadruple the maximum kinetic energy of the electrons ejected from this surface.

Consider the three basic quantities of a circuit: voltage (potential difference), current, and resistance.

In general terms, describe each one in your own words and its basic characteristic/property, and can you do an analogy of these quantities with a fluid system, say a stream of water?

Further, since many of you are in the medical field, can you relate a basic circuit and its components to a system of the body, maybe the circulatory system? If, what is the analogy between the basic circuit components to components of the circulatory system?

Please no handwritten or picture respones - only typed replies

Compare and contrast the photon nature of light with the wave nature of light, making sure to address the following properties:

a: color

b: intensity

C: energy

Chapter 08, Problem 024. A block of mass m = 1.30 kg is dropped from height h = 59.0 cm onto a spring of spring constant k = 1130 N/m (see the figure). Find the maximum distance the spring is compressed.

The plane of a rectangular loop of wire with a width of 5.0 cm and a height of 8.0 cm is parallel to a magnetic field of magnitude 0.22 T . The loop carries a current of 6.7 A .

What torque acts on the loop?

What is the magnetic moment of the loop?

What is the maximum torque that can be obtained with the same total length of wire carrying the same current in this magnetic field?

In Example 2.6, we considered a simple model for a rocket launched from the surface of the Earth. A better expression for a rocket's position measured from the center of the Earth is given by y(t) = RE3/2 + 3 g 2 REt 2/3 where RE is the radius of the Earth (6.38 ✕ 106 m) and g is the constant acceleration of an object in free fall near the Earth's surface (9.81 m/s2). (a) Derive expressions for vy(t) and ay(t). (Use the following as necessary: g, RE, and t. Do not substitute numerical values; use variables only.) vy(t) = √ g 2 ​2R E ​(R ( 3 2 ​) E ​+3√ g 2 ​R E ​t)(− 1 3 ​) m/s ay(t) = m/s2 (b) Plot y(t), vy(t), and ay(t). (A spreadsheet program would be helpful. Submit a file with a maximum size of 1 MB.) This answer has not been graded yet. (c) When will the rocket be at y = 4RE? Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. s (d) What are vy and ay when y = 4RE? (Express your answers in vector form.) vy(t) = m/s ay(t) = m/s2

The intensity of sunlight under the clear sky is 1030 W/m2 . How much electromagnetic energy is contained per cubic meter near the Earth’s surface? The speed of light is 2.99792 × 108 m/s. Answer in units of J/m3 .

What is the maximum radiation pressure that can be exerted by sunlight in space of intensity 3693 W/m2 on a flat black surface? The speed of light is 3 × 108 m/s. Answer in units of Pa.

Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 4.00 s, it rotates 13.2 rad. During that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular velocity? (c) What is the instantaneous angular velocity of the disk at the end of the 4.00 s? (d) With the angular acceleration unchanged, through what additional angle (rad) will the disk turn during the next 4.00 s?