Thursday, October 28, 2010
Thurs-Day 1
AP Chem and Physics: good thing- the Blackboard glitch was repaired so files from today are currently being uploaded.
Physics - the HW is to do question 8 of the Forces 3 worksheet.
Today, we did the most challenging problem of the year. Drawing a free-body diagram of an object on an inclined plane. Part of the difficulty is in resolving the weight of the object into its components that are parallel and perpendicular to the incline plane. The other difficulty is seeing that the normal force is LESS than it would be on a flat horizontal surface because the normal force will equal ONLY the VERTICAL/perpendicular to the inclined plane component of the object's weight. Also, for a non-accelerating object, the FRICTIONAL force will be equal and opposite to the horizontal/parallel component of the object's weight.
It will take some practice to be comfortable with these more complex setups. We will also do some problems where the object actually accelerates down the inclined plane.
AP Chem- further discussed the experimental evidence with EMR that led to the Bohr model of the atom.
In AP Chem, the last posted practice test, without the answer key, has an ERROR in question 5.
The reaction is between potassium carbonate and NITRIC ACID (not aluminum nitrate)!
The other information is correct.
7PM - that file has now been corrected.
See yesterday's post for a list of question types on tomorrow's test.
Practice writing your explanations and doing more practice problems.
Physics - the HW is to do question 8 of the Forces 3 worksheet.
Today, we did the most challenging problem of the year. Drawing a free-body diagram of an object on an inclined plane. Part of the difficulty is in resolving the weight of the object into its components that are parallel and perpendicular to the incline plane. The other difficulty is seeing that the normal force is LESS than it would be on a flat horizontal surface because the normal force will equal ONLY the VERTICAL/perpendicular to the inclined plane component of the object's weight. Also, for a non-accelerating object, the FRICTIONAL force will be equal and opposite to the horizontal/parallel component of the object's weight.
It will take some practice to be comfortable with these more complex setups. We will also do some problems where the object actually accelerates down the inclined plane.
AP Chem- further discussed the experimental evidence with EMR that led to the Bohr model of the atom.
In AP Chem, the last posted practice test, without the answer key, has an ERROR in question 5.
The reaction is between potassium carbonate and NITRIC ACID (not aluminum nitrate)!
The other information is correct.
7PM - that file has now been corrected.
See yesterday's post for a list of question types on tomorrow's test.
Practice writing your explanations and doing more practice problems.
# posted by C @ 2:40 PM 
