Physics week 1

Overview

Posting Instructions:

1. You must choose THREE of the questions listed below to answer/discuss. Read through the ten choices below and make your decision.
2. Create your response to the assignment questions.
3. Click on Week 1 Physics Talk, above.
4. Click on the Create Thread Button at the top of the page to post your main response to the weekly discussion, by 11:59 PM ET Thursday Week 1.
5. Click Reply when in a classmate's thread post to nest your responses under that main post. You must create two substantive replies by 11:59 PM ET Sunday Week 1.

For your first post, choose three of the questions below to address:

• Question 1: Firing a gun into the air. Suppose a bullet is fired straight upwards and that it leaves the barrel of the gun at 200 m/s. Neglecting air resistance, how fast will it be going when it comes down? What will happen to a person who happens to be where the bullet comes down?
• Question 2: Same question as above, but - one approach to solving problems is to start with an "idealized case". In the question above we made the approximation that air resistance was negligible, then we say, "What happens if we make the situation less ideal?"
• Question 3: In this case we'll say, "Now let's consider what effect air resistance might have." Take a look at the discussion of terminal speed in your textbook. What does that suggest will be the speed of the bullet when it comes down?
• Question 4: Now suppose we fire the gun at an angle instead of straight up. What difference will that make to the result?
• Question 5: Is the egg raw or hard boiled? Suppose there's an egg in your refrigerator but you don't remember whether you boiled it or not. You could try breaking it, but that's a messy and not very useful way to do it. What other method can you think of to determine if the egg is raw or hard boiled? Hint: Consider Newton's Laws of Motion. A raw egg contains a soft yolk floating around in a liquid. If you suddenly impart a motion to the shell, will the insides pick up the motion quickly? Can anything "slosh around" inside a hard-boiled egg?
• Question 6: Monkey in a tree. A monkey is hanging from a tree branch. A coconut is fired in a perfectly horizontal direction, toward the monkey as a target. The monkey sees the coconut being fired toward him and lets go of the branch. Assume that the monkey reacts instantaneously. Will the monkey catch the coconut? Suppose that the monkey and the weapon were 25 meters apart and the coconut travels at a speed of 25 m/s. NEGLECTING AIR RESISTANCE, will the monkey catch the coconut??
• Question 7: Are "idealized cases" useful? Is it useful to first consider an "idealized case" and then ask, "What happens to our answer when we make our assumptions more realistic?"
• Question 8: State Newton's first law of motion and give an example of what it means.
• Question 9: State Newton's second law of motion and give an example of what it means.
• Question 10: State Newton's third law of motion and give an example of what it means.

Your initial response to this week's discussion should be well-written in your own words, paraphrasing from your sources. Putting only the question number in your post is not enough, you have to include the whole question to which you are responding. You must also cite at least one credible academic reference source in text and provide full end ref information in APA format. The initial post must be at least 300-400 words and is due by 11:59 PM ET Thursday Week 1.