Solving Physics Problems 9/20/13

Bellwork Which of the following is not a vector? Which of the following is not a vector? –Displacement, Time, Acceleration or Velocity

The RIDGES Strategy R – Read R – Read I – Identify & Information I – Identify & Information D – Draw D – Draw G – Generate G – Generate E – Evaluate & Equation(s) E – Evaluate & Equation(s) S – Solve S – Solve

The RIDGES Strategy with T-Charts R – Read the problem carefully! R – Read the problem carefully! I – Identify what you are looking for and the Information that is given. I – Identify what you are looking for and the Information that is given. (1 & 2 in T-Chart) D – Draw a picture of the problem. D – Draw a picture of the problem. G – Generate a plan (T-Chart) G – Generate a plan (T-Chart) E – Evaluate the Equation(s) that can help solve the problem (3 T-Chart) E – Evaluate the Equation(s) that can help solve the problem (3 T-Chart) S – Solve the problem and answer with the appropriate units (4 & 5 in T-Chart) S – Solve the problem and answer with the appropriate units (4 & 5 in T-Chart)

What Equation Do I Use? The “I” in RIDGES and boxes 1 and 2 in the T-Chart answers this question! The “I” in RIDGES and boxes 1 and 2 in the T-Chart answers this question! You need to know what you are looking for and what is given to determine the equation. You need to know what you are looking for and what is given to determine the equation. Sometimes the variable you are looking for will not be isolated Sometimes the variable you are looking for will not be isolated (i.e.) it is on the right side in the equation

Key Words and Clues Time – How long, duration, etc. Time – How long, duration, etc. look for units (s, min, hr, ms) Distance/Displacement – How far, what height, depth, length, dimensions, etc. Distance/Displacement – How far, what height, depth, length, dimensions, etc. look for units (m, cm, km, miles)

Key Words and Clues Velocity – How fast, what speed, traveling, going, etc. Velocity – How fast, what speed, traveling, going, etc. look for units (m/s, km/hr, ft/s, mph) Acceleration – Speeds up, slows down Acceleration – Speeds up, slows down look for units (m/s 2, ft/s 2 )

Due Dates and Calendar Tues. (9/24): S.G. # and Free Fall Problems Tues. (9/24): S.G. # and Free Fall Problems Wed. (9/25): Linear Motion Review Wed. (9/25): Linear Motion Review Thurs. (9/26): Test - Part 1 Thurs. (9/26): Test - Part 1 –Multiple Choice, Short Answer, Vectors and Scaling Friday (9/27): Test - Part 2 Friday (9/27): Test - Part 2 –Velocity, Acceleration and Free Fall Problems

Monday? There is a lot due next week for this class There is a lot due next week for this class If you are using you time wisely then I’ll give you time to work on Monday If you are using you time wisely then I’ll give you time to work on Monday If you are not work on my assignment then I’ll move onto projectile motion on Monday If you are not work on my assignment then I’ll move onto projectile motion on Monday

Examples EX 1) A car is traveling at 24.1 m/s along the highway when it enters a construction zone where it slows down to 8.75 m/s in 5.21 s. What is the cars acceleration? EX 1) A car is traveling at 24.1 m/s along the highway when it enters a construction zone where it slows down to 8.75 m/s in 5.21 s. What is the cars acceleration? EX 2) On the Moon, a feather is dropped from a height of 1.44 m, and takes 1.31 seconds to hit the ground. Determine the acceleration of gravity on the Moon. EX 2) On the Moon, a feather is dropped from a height of 1.44 m, and takes 1.31 seconds to hit the ground. Determine the acceleration of gravity on the Moon. EX 3) At what speed will a softball hit the ground if it is dropped from the bleachers that are at a height of 6.7 m? EX 3) At what speed will a softball hit the ground if it is dropped from the bleachers that are at a height of 6.7 m?