astronomy chapter 3 4

Pluto's orbit is more eccentric than any of the major planets. What does that mean?

orbit is of Pluto is less circular

Why is Tycho Brahe often called "the greatest naked-eye astronomer" of all time?

because he had extended obversvation without a telescope

What is the phase of the Moon during a total solar eclipse? During a total lunar eclipse?

full moon

Which of these properties of an object best quantifies its inertia: velocity, acceleration, volume, mass, or temperature?

mass

Why is it difficult to construct a practical calendar based on the Moon's cycle of phases?

not enough days for the whole year.

Explain why there are two high tides and two low tides each day. Strictly speaking, should the period during which there are two high tides be 24 hours? If not, what should the interval be?

the top of the force of the moon creates bulges.

Which has more mass: an armful of feathers or an armful of lead? Which has more volume: a kilogram of feathers or a kilogram of lead? Which has higher density: a kilogram of feathers or a kilogram of lead?

1) armful of lead (mass is related to weight) 2) Kg of feathers has more volume as it is less dense. 3) Lead has higher density

State Kepler's three laws in your own words.

1st- The planets orbits in an elliptical [oval] shape.The sun is at one focus.The second focus is not needed because of sun's mass & gravity. 2nd- A planet spends equal amount of time [in its orbit] perihelion & aphelion. 3rd- How long it takes a planet to orbit the sun is related to how far the plant is from the sun like a track. ex: 4yrs=a^3 mars is 2 earth years away 2^2=a^3 4= a^3 1.58 au

The gas pedal, the brakes, and the steering wheel all have the ability to accelerate a car—how?

The gas pedal is used to accelerate the car that is to increase the speed of the car. The brakes are used to do decelerate the car that is to decrease the speed of the car. The steering wheel is used to give direction to the car. It is used to change direction of the car. In all three cases, the speed or the direction of the car is changed and as per the definition of the acceleration all of these are said to be accelerating the car.

Why did Kepler need Tycho Brahe's data to formulate his laws?

To deduce a universal theory for motion of planets, Kepler needed data which supports heliocentric model, and Brahe was having records which deviated from the Ptolemic model and Kepler believed in Brahe. That's why Kepler was in need of Brahe's data.

What are the two ways that the tilt of Earth's axis causes the summers in the United States to be warmer than the winters?

during the summer more derect sunlight and more daylight

What is the latitude of the North Pole? The South Pole? Why does longitude have no meaning at the North and South Poles?

90; -90 no east west if you are at the south pole only south.

Which major planet has the largest . . . A. semimajor axis? B. average orbital speed around the Sun? C. orbital period around the Sun? D. eccentricity?

A. Neptune has the largest semi major axis. B. Mercury has the highest average orbital speed around the sun. C. Neptune has the highest orbital period around the sun. D. Mercury has the highest eccentricity.

The term equinox translates as "equal night." Explain why this translation makes sense from an astronomical point of view.

Equinox literally translates into "equal night" referring to the fact that on these days the amount of night and the amount of day are equal (12 hours each).

Why was Brahe reluctant to provide Kepler with all his data at one time?

He feared Kepler will come out with a universal theory for planetary motion and thereby taking all the credit by himself.

What was the great insight Newton had regarding Earth's gravity that allowed him to develop the universal law of gravitation?

In Newtons era, the gravity was thought to be related to earth alone. But Newton's insight was that the earth gravity may go further for the interaction of planets with the sun and the moons with the earth and other planets. he thought of the motion of celestial bodies around other celestial bodies is all due to gravity. He believed that all the bodies in the universe attract every other matter or object.

Explain how Kepler was able to find a relationship (his third law) between the orbital periods and distances of the planets that did not depend on the masses of the planets or the Sun.

In the year 1619, he came out with a relation between orbit of the planet and their relative distances from the sun. The relation was as follows P^2=a^3. Here P represents the orbital period and a represents The average distance from the sun. The relationship is now known as Kepler's third law of planetary motion.

Write out Newton's three laws of motion in terms of what happens with the momentum of objects.

It is defined as the product of mass of the moving object and the velocity with which it is moving. It depends on three factors; its speed, its mass and the direction of motion.

Why do we say that Neptune was the first planet to be discovered through the use of mathematics?

John Couch Adams of Britain and Urbain Jean Joseph Leverrier of France, used mathematics to predict that the gravity from another planet beyond Uranus was affecting the orbit of Uranus. They figured out not only where the planet was, but also how much mass it had.

To calculate the angular momentum of an object, which properties of an object do you need to know?

The angular momentum of an object depends on the following properties of an object, 1. Mass of the rotating object 2. Velocity of the rotating object 3. Radius of path in which the object moves 4. The angle subtended by the path

To calculate the momentum of an object, which properties of an object do you need to know? 100 Chapter 3 Orbits and Gravity

The momentum of a body depends upon the following 1.Mass of the body 2. velocity of the body

According to Kepler's second law, where in a planet's orbit would it be moving fastest? Where would it be moving slowest?

When planets are closer to the sun moves faster. When the planet is farther from the sun the speed of the planet is slow.

Explain how a rocket can propel itself using Newton's third law.

When the fuel's inside the rocket burn, the exhaust gases are released Into the atmosphere. These exhaust gases are directed towards the ground, from the rocket. This produces a very large fours on the ground. Here, according to the third law of motion there will be a reaction force. Force due to the exhaust gases which cause the rocket to lift up, acts as a reaction force. And thus the rocket propels itself using the third law of motion