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Classical PhysicsYear 10 Pathway C

Mr. D. Patterson

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Outcomes Describe the concepts of distance,

displacement, speed and velocity

Use the formula v=s/t to calculate the unknown variable for uniform velocity questions.

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Scalars and Vectors

The study of motion uses several variables; some of these are scalars and some are vectors.

Scalar Quantities: symbol (unit) Vector Quantities: symbol (unit)

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Distance vs Displacement Distance is the length travelled to get from the starting

point to the end point. It is a scalar.

Displacement is the change in position from some starting point to some end point. It is a vector

(Think of it like the shortest path from start to finish)

10km

10km

10kmDistance travelled is 30km

Displacement is 10km East

10km

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1km1km

0.5 km 3 km

2 km

1.5 km 0.5 km

What is my distance covered at the end of my journey?What is my displacement at the end of my journey?

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A train heads south for 3km then east for 5km and finally north for 3km.

Draw a vector diagram of the journey What is the distance of the journey? What is the displacement of the journey?

Examples

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Velocity is a measure of “fastness”

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Speed vs Velocity Speed is a measure of how fast an object travels. Average speed is dependent on the distance

travelled and how long it takes. It is a scalar.

Average velocity is dependent on the displacement and how long it takes. It is a vector

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Some simple equations in physics can make use of the “magic triangle”

No good at algebra?

vs

t

Need to find s? Cover it up

Need to find v? Cover it up

Need to find t? Cover it up

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Scalars and VectorsScalar Quantities: symbol (unit) Vector Quantities: symbol (unit)

Distance: s (m) Displacement: s (m)

Speed: v (m/s) Velocity: v (m/s)

Time: t (s)

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1) If a ball rolls 10 m in 2 s, what is its speed?

2) If a car is travelling at 15ms-1 for 30 seconds, how far does it travel?

3) How long does it take to run a 100m race if running at 9.5 ms-1?

4) What is the speed of an athlete who completes a 400 m lap in 56 s? What is the athletes average velocity?

Example

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1) If a ball rolls 10 m in 2 s, what is its speed?

2) If a car is travelling at 15ms-1 for 30 seconds, how far does it travel?

3) How long does it take to run a 100m race if running at 9.5 ms-1?

Example

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4) What is the speed of an athlete who completes a 400 m lap in 56 s? What is the athletes average velocity?

Example

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Outcomes Describe the concepts of distance,

displacement, speed and velocity

Use the formula v=s/t to calculate the unknown variable for uniform velocity questions.

Matthew and Winters Set 6 (basic), Set 7 (advanced)