Which assumption is true of an ideal gas?

a. The gas has volume because the particles take up space.
b. The particles experience no inter-molecular attractive forces.
c. The particles undergo inelastic collisions with the surface of their container.
d. The ideal gas model is not accurate under most conditions.

A swimmer is peacefully floating motionless in a lake. Determine the fraction of the

total volume of her body which remains visible above the water, given that the density

of her body is 920 kg/m3, and the density of the lake water is 1025 kg/m3.

The moon has a mass of about 7.3x1022kg amd a radius of 1738km.

a)Calculate the escape speed from the surface of the moon. Express the answer in km/sec.

b) A spacecraft of mass 250kg is launched from the surface of the moon at a speed of 1500m/sec. Using conservation of mechanical energy, compute the maximum distance reached by the spacecraft, at which the spacecraft comes to a stop.
c) if the spacecraft is launched with an initial speed of 5500m/sec from the surface of the moon, use conservation of mechanical energy to determine how fast the spacecraft will be traveling when it is very far from the moon.

It seems the universe is full of angular momentum. Planets revolve and orbit stars, stars revolve and orbit galactic centres even sub atomic particles spin.

Yet the origin of the universe was the big bang where everything exploded outward froma point source. As I understand it there is a law of conservation of angular momentum saying it cannot be created or destroyed onlt transferred. So I am puzzled where did all the angular momentum come from?

1). Explain the following issues with a short essay (with total number of words less than 300)

(a) Gauss law in electrostatics.

(b) Ampere’s law in magnetostatics.

(c) Faraday’s induction law.

(d) Displacement current.

Consider a two-dimensional universe where Maxwell's equations are valid (their corresponding two-dimensional). Derive a wave equation.

When an object is located very far away from a convex mirror, the image of the object is 12.0 cm behind the mirror. Using a ray diagram drawn to scale, determine where the image is located when the object is placed 6.0 cm in front of the mirror. Note that the mirror must be drawn to scale also. In your drawing, assume that the height of the object is 3.0 cm.
cm  ---Select--- in front of behind the mirror

As an aid in working this problem, consult Concept Simulation 25.2.

A 5.0-cm-high object is situated 16.0 cm in front of a concave mirror that has a radius of curvature of 8.0 cm. Use a ray diagram drawn to scale, measure the following. The mirror must be drawn to scale.

(a) the image distance (include the sign)
cm  ---Select--- in front of the mirror in back of the mirror

(b) the height of the image
cm  ---Select--- upright inverted

An extremely thin sheet of glass is being inspected at the factory. Illuminated by white light at near-normal incidence, the film-like sheet is 0.402 µm thick and has air on both sides. If the glass has a refractive index of 1.52, what wavelength of visible light (in nm) does it reflect most strongly? (The wavelengths of visible light range from 400 to 700 nm.)

A radio antenna broadcasts a 1.0 MHz radio wave with 29.0 kW of power. Assume that the radiation is emitted uniformly in all directions.

What is the wave's intensity 25.0 km from the antenna?

The answer is 3.69×10⁻⁶ W/m^2

What is the electric field amplitude at this distance?

A 336-kg crate rests on a surface that is inclined above the horizontal at an angle of 17.2°. A horizontal force (magnitude = 405 N and parallel to the ground, not the incline) is required to start the crate moving down the incline. What is the coefficient of static friction between the crate and the incline?

A catapult launches a test rocket vertically upward from a well, giving the rocket an initial speed of 80.8 m/s at ground level. The engines then fire, and the rocket accelerates upward at 4.20 m/s2 until it reaches an altitude of 990 m. At that point its engines fail, and the rocket goes into free fall, with an acceleration of ❝9.80 m/s2. (You will need to consider the motion while the engine is operating and the free-fall motion separately.)

(a) For what time interval is the rocket in motion above the ground? s

(b) What is its maximum altitude? km (

c) What is its velocity just before it hits the ground? m/s

1. Three 1500 Ω resistors are wired in parallel with a 15 V battery. What is the current through each of the resistors?
2. Three 1500 Ω resistors are wired in parallel with a 15 V battery. What is the current through the battery?
3. Can any arbitrary combination of resistors be broken down into series and parallel combinations?
4. Three resistors (110 Ω, 2500 Ω, and 5800 Ω) are wired together in series with a 12 V battery. What is the current through each of the resistors?
5. Three resistors (110 Ω, 2500 Ω, and 5800 Ω) are wired together in parallel with a 12 V battery. What is the current through each of the resistors?

When do the centers of gravity and mass coincide? When they don’t? Explain why is the center of gravity of the Flame Towers (building in Baku, lookup in google) is a bit below their center of mass?

1-Why doesn't the force of gravity change the speed of a satellite in circular orbit?

2-A circularly moving object requires a centripetal force. What supplies this force for satellites that orbit the Earth?

3-A 'geosynchronous' Earth satellite can remain nearly directly overhead in Singapore, but not in San Francisco. Why?

4-True or false: For orbits of greater altitude, the period is longer.

5- Fill in the blank:

____(a)______gathered the data that were used to show that the planets travel in elliptical orbits around the sun___(b)_______discovered the orbits were elliptical.______(c)_______explained them.

Question 4(3pts)

State the definitions of elastic, inelastic, and completely inelastic collisions. Give an example of a situation where the final kinetic energy is greater than the initial value.