the big question: how strong is our sun? why are we learning this? the sun is dying, slowly…

The big question:How strong is our sun?

Why are we learning this?

The sun is dying,slowly…

Homework:

P139 q1

Learning Objective: To combine knowledge on speed, power output and intensity

The big question:How strong is our sun?

A – Evaluate efficiency, power and intensityB – Predict sound intensity and predict reasons for inaccuracyC – Calculate the sun’s power for different planetsD – Identify intensity/amplitude relationship

Plot 2 waves on displacement-time graphs,one with amplitude TWICE the size of the other, but both in phase

Speed = gradient of a wave. At displacement 0, draw on the gradients

(C) Plot a wavewith halfthe gradient ofthe smaller one

Plot 2 waves on displacement-time graphs,one with amplitude TWICE the size of the other, but both in phase

Speed = gradient of a wave. At displacement 0, draw on the gradients

If 1 gradientis twice the other,one speed is twice

KE= ½ mv2

Learning Objective: To combine knowledge on speed, power output and intensity

The big question:How strong is our sun?

A – Evaluate efficiency, power and intensityB – Predict sound intensity and predict reasons for inaccuracyC – Calculate the sun’s power for different planetsD – Identify intensity/amplitude relationship

For your task you need to provide:

- AN EXPLANATION- A SHEET OF WRITING YOU CAN GIVE TO THE OTHER GROUP- 3 QUICK NUMERICAL QUESTIONS FOR THEM, WITH ANSWERS- KEY PHRASES (WORDS+MEANINGS)

On whiteboards again…

The sun’s power output is 3.7 x 1023 kWIts distance to earth is 1.5x1011 m

Neptune is 30 times further from the sun than earth.

Calculate what the power output to Neptune is

Learning Objective: To combine knowledge on speed, power output and intensity

The big question:How strong is our sun?

A – Evaluate efficiency, power and intensityB – Predict sound intensity and predict reasons for inaccuracyC – Calculate the sun’s power for different planetsD – Identify intensity/amplitude relationship

Pick a question, and complete in pairs..

(B) P144 q4

(A) P144 q5

He said she said…

Mr Singh (B) says “Minimum energy to blow a car window is 0.5W. A 10W circular subwoofer 1m away from the back-window would be safe”

Mrs Brown (A) says “If minimum energy necessary to keep earth alive is 1012W,and the sun loses 50% of its 3.7 x 1023 kW power, we could be 100m away and still die”

Are they correct? Why?

Learning Objective: To apply use of wave analysis

The big question:How can we analyse a wave?

A – Predict values using wave termsB – Evaluate consistency across wave termsC – Calculate wave terms for a variety of wavesD – Understand the 6 key wave terms