Homework for 4/30/2007

Post-instructional survey 4: Posted at my web page

Homework 121. How would phases change if the Moon were the same size as Earth, but still had the same mass?

The phases would be the same shape, but the visible portion of the moon would appear larger to the eye.

3 correct answer or drawing

2 incorrect answer or drawing

1 attempt, but both answer and drawing incorrect

Homework 112. How would tides change if the Moon were the same size as Earth, but still had the same mass?

The tides would be mostly unaffected because the mass of the Moon would remain the same and so the gravitational force would be nearly the same. There would be different distances of parts of the Moon from the Earth, but that would result in a very small effect.

3 correct answer or drawing

2 incorrect answer or drawing

1 attempt, but both answer and drawing incorrect

Drawings not to scale.

Homework 113. How would eclipses change if the Moon were the same size as Earth, but still had the same mass?

Both total and partial solar eclipses would be more frequent because there is a greater chance that the larger Moon would block the Sun. The Earth will have more Moon to block, but a bigger target. Their will be more partial lunar eclipses and fewer total lunar eclipses.

4 correct answer and drawing

3 correct answer or drawing (not both)

2 incorrect answer or drawing

1 attempt, but both answer and drawing incorrect

Drawings not to scale.

We live about 100 yrsStars like our Sun live about 10,000,000,000 yrs

If we studied a star all of our life we could seeonly a small fraction of the star’s life.

1000000001

So how do we know anything about the life of a star?

Meet Zip from Ip

Zip and his kind live only about 30 seconds and we live about 100 yrs.

Zip has the same problem observing us.

If zip studied us all of his life he could seeonly a small fraction of our life.

1000000001

So what can Zip do?

Zip is very intelligent and very fast. He can take measurements of a lot of different people and try to make sense of them.

Classification Activity

Edward Pickering’s “computers”

Williamina Fleming

Annie Jump Cannon

Antonia Maury

Cecilia Payne-Gaposchkin

Taking the temperature of stars

Well-known

Nearest

Brightest

Hipparcos – 20,000

A thimble full of neutron star material would weigh around 100 million tons – a good sized terrestrial mountain.

A 70 kg person standing on the surface of a typical neutron star would weigh around 1 million tons. The person would be flattened to much less than the thickness of a sheet of paper due to the differential pull of gravity.

Watching an robot astronaut approach the event horizon (the point where light can’t escape) from a safe distance we would observe

-> light from his flashlight would be shifted to longer wavelengths (red shifted) until it was no longer visible to the human eye -> his watch would appear to run more slowly

Everything would appear perfectly normal to the robot until he crossed the event horizon.

A Trip Through the Universe

Hundreds of billions of galaxies with hundreds of billions of stars

Material from which the final exam will be drawn:

A. Text and handout content readings.B. Diagnoser assignments.C. Pre/Post-assessment.D. Classroom activities (notebooks).E. Homework.F. Power Points from class.

The exam will have:

A. Short discussion questions.B. Multiple choice.C. Question(s) on a live

demonstration.D. Performance part.

Classroom Activities Since Exam 2:

A. NASA CONNECT Virtual EarthB. Predicting the WeatherC. Food WebD. Water CycleE. Earth Station ActivitiesF. Sun-Earth-Moon RelationshipsG. Classification of Stars

Principles and Fundamental Concepts:

A. Earth systemsB. Earth cyclesC. Earth structureD. Earth processesE. Earth-Moon-Sun connectionF. Planetary systemG. Stars and Galaxies