Solving Thought Problems Or Questions?

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Solving Thought ProblemsOr Questions?

• Thought problems are question problems which
  ask you to explain a situation or a phenomena.

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Solving Thought ProblemsOr Questions?

• Thought problems are question problems which
  ask you to explain a situation or a phenomena.
• One reads the problem, selects a law of
  physics and applies that law to solve the
  question.

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Solving Questions

• Often that is not sufficient to solve the
  question, so one has to Read the question Over
  and Apply Reason. This is the ROAR process.

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Solving Questions

• Often that is not sufficient to solve the
  question, so one has to Read the question Over
  and Apply Reason. This is the ROAR process.
• This involves asking the questions

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Solving Questions

• Often that is not sufficient to solve the
  question, so one has to Read the question Over
  and Apply Reason. This is the ROAR process.
• This involves asking the questions
• What is the question trying to find?

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Solving Questions

• Often that is not sufficient to solve the
  question, so one has to Read the question Over
  and Apply Reason. This is the ROAR process.
• This involves asking the questions
• What is the question trying to find? What
  does the statement of the question mean?

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ROAR

• What physical law can I use ?

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ROAR

• What physical law can I use ?
• How would it apply to this problem?

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ROAR

• What physical law can I use ?
• How would it apply to this problem?
• Have I ever experienced this?

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ROAR

• What physical law can I use ?
• How would it apply to this problem?
• Have I ever experienced this?
• The law seems to apply to the problem, but there
  is a problem!

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ROAR

• What physical law can I use ?
• How would it apply to this problem?
• Have I ever experienced this?
• The law seems to apply to the problem, but there
  is a problem!
• Can I solve that problem which arose?

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Example Question

• Under what circumstances might something be
  weightless?

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Example Question

• Under what circumstances might something be
  weightless?
• Question asks for the situations when an object
  might be weightless.

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Example Question

• Under what circumstances might something be
  weightless?
• Question asks for the situations when an object
  might be weightless.
• Situation I have never seen anything not have
  weight.

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Example Question

• Under what circumstances might something be
  weightless?
• Question asks for the situations when an object
  might be weightless.
• Situation I have never seen anything not have
  weight.
• The Law of Universal Gravitation says that all
  bodies have weight W m g

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Question Solving Continued.

• So how can an object have weight, but be
  weightless?

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Question Solving Continued.

• So how can an object have weight, but be
  weightless? (New problem to solve)

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Question Solving Continued.

• So how can an object have weight, but be
  weightless? (New problem to solve)
• Reasoning Why do we feel weight ?

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Question Solving Continued.

• So how can an object have weight, but be
  weightless? (New problem to solve)
• Reasoning Why do we feel weight ?
• It is the force of the object against a
  surface. For example I feel weight because my
  feet are touching the ground.

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Question Solving Continued.

• So how can an object have weight, but be
  weightless? (New problem to solve)
• Reasoning Why do we feel weight ?
• It is the force of the object against a
  surface. For example I feel weight because my
  feet are touching the ground.
• How can I make my feet touch no surface?

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Question Solving Continued

• Hmmm, let me think of an example of when I cant
  feel something against my feet ?

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Question Solving Continued

• Hmmm, let me think of an example of when I cant
  feel something against my feet ?
• Oh yes, when I jump from a high place to a low
  place, when Im falling I cant feel any weight.
  Like when Im jumping into the swimming pool, or
  diving.

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Question Solving Continued

• Oh yes, I remember seeing the astronauts float
  around in space, certainly they are weightless.

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Question Solving Continued

• Oh yes, I remember seeing the astronauts
• float around in space, certainly they are
  weightless.
• Yes I remember at camp, they used to throw us
  into the air from a large blanket
• I remember how I felt then like I was
  floating in space.

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Question Solving Continued

• Oh yes, I remember seeing the astronauts
• float around in space, certainly they are
  weightless.
• Yes I remember at camp, they used to throw us
  into the air from a large blanket
• I remember how I felt then like I was
  floating in space.
• These last three examples are all answers!

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SOLVING QUANTATITIVE PROBLEMS

• GURU CA METHOD

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SOLVING QUANTATITIVE PROBLEMS

• GURU CA METHOD
• G Write Down the GIVENS ( Assign a symbol and
  unit for each value.)

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SOLVING QUANTATITIVE PROBLEMS

• GURU CA METHOD
• G Write Down the GIVENS ( Assign a symbol and
  unit for each value.)
• U Write down the UNKNOWN (Assign a symbol and
  unit)

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SOLVING QUANTATITIVE PROBLEMS

• GURU CA METHOD
• G Write Down the GIVENS ( Assign a symbol and
  unit for each value.)
• U Write down the UNKNOWN (Assign a symbol and
  unit)
• R Select a RELATIONSHIP (equation)

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SOLVING QUANTATIVE PROBLEMS (Contd)

• U Determine if the UNITS desired can be directly
  determined from the givens. If not convert to the
  proper unit.

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SOLVING QUANTATIVE PROBLEMS (Contd)

• U Determine if the UNITS desired can be directly
  determined from the givens. If not convert to the
  proper unit.
• C Substitute the values in the equation and
  CALCULATE the unknown.

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SOLVING QUANTATIVE PROBLEMS (Contd)

• U Determine if the UNITS desired can be directly
  determined from the givens. If not convert to the
  proper unit.
• C Substitute the values in the equation and
  CALCULATE the unknown.
• A State the ANSWER with its unit.

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• As a 2 kg ball rolls down a ramp, the net force
  on it is 10 N. What is the acceleration ?

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• As a 2 kg ball rolls down a ramp, the net force
  on it is 10 N. What is the acceleration ?
• G m 2 kg
• F 10 N

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• As a 2 kg ball rolls down a ramp, the net force
  on it is 10 N. What is the acceleration ?
• G m 2 kg
• F 10 N
• U a ? (m/s2)

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• As a 2 kg ball rolls down a ramp, the net force
  on it is 10 N. What is the acceleration ?
• G m 2 kg
• F 10 N
• U a ? (m/s2)
• R a F/m

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• As a 2 kg ball rolls down a ramp, the net force
  on it is 10 N. What is the acceleration ?
• G m 2 kg U N/kg m/s2
• F 10 N
• U a ? (m/s2)
• R a F/m

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• As a 2 kg ball rolls down a ramp, the net force
  on it is 10 N. What is the acceleration ?
• G m 2 kg U N/kg m/s2
• F 10 N
• U a ? (m/s2) C a 10 N/2 kg
• R a F/m

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• As a 2 kg ball rolls down a ramp, the net force
  on it is 10 N. What is the acceleration ?
• G m 2 kg U N/kg m/s2
• F 10 N
• U a ? (m/s2) C a 10 N/2 kg
• R a F/m A a 5 m/s2

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• A child weighs 300 N. What is the childs mass ?

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• A child weighs 300 N. What is the childs mass ?
• G W 300 N
• g 9.8 m/s2

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• A child weighs 300 N. What is the childs mass ?
• G W 300 N
• g 9.8 m/s2
• U m ? ( kg)

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• A child weighs 300 N. What is the childs mass ?
• G W 300 N
• g 9.8 m/s2
• U m ? ( kg)
• R m W/g

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• A child weighs 300 N. What is the childs mass ?
• G W 300 N U N/m/s2 kg
• g 9.8 m/s2
• U m ? ( kg)
• R m W/g

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• A child weighs 300 N. What is the childs mass ?
• G W 300 N U N/m/s2 kg
• g 9.8 m/s2
• U m ? ( kg) C m 300 N/9.8 m/s2
• R m W/g

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EXAMPLE SOLVING A PROBLEM BY GURU CA

• A child weighs 300 N. What is the childs mass ?
• G W 300 N U N/m/s2 kg
• g 9.8 m/s2
• U m ? ( kg) C m 300 N/9.8 m/s2
• R m W/g A m 30.6 kg