Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms...

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Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1 . a) What distance is covered along the course of acceleration? b) What was the bike’s initial velocity?

Transcript of Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms...

Page 1: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Do Now

A motorbike accelerates at 2.6 ms-2 for 4 seconds until it reaches the new speed of 25 ms-1.

a) What distance is covered along the course of acceleration?

b) What was the bike’s initial velocity?

Remember - KUFSS

Page 2: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Using Kinematic Equations 2

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Page 3: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Five Variables, Five Equationsvi vf d a t

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Page 4: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

WarningThe 5th equation will not appear on the formulae sheet supplied on the examination day.

221 attvd f

Page 5: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

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221 attvd f

Solution: Memorise(hint – notice how the 5th equation looks

strikingly similar to the 4th equation)

Page 6: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Five Variables, Five Equationsvi vf d a t

atvv if

221 attvd i

tvv

d fi

2

advv if 222

221 attvd f

Page 7: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Ponder this:What if a = 0? (no acceleration)

atvv if

221 attvd i

tvv

d fi

2

advv if 222

221 attvd f

Page 8: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Question ONE

A rock is dropped from the roof of a 23 m tall building. As it falls, it accelerates at 9.8 ms-2.

a) What is the speed of the rock at the moment it hits the ground?

b) How long does it take to reach the ground?

Remember - KUFSS

Page 9: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Question TWO

A running train decelerates at 1.3 ms-2 then it comes to a stop after 47 s.

a) What distance has the train covered since it started to slow down?

b) At what velocity was the train going before it began to slow down?

Page 10: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Acceleration due to gravity

g = 9.8 ms-2 ↓

ANY object’s motion that is under the influence of the Earth’s gravity, is subject to the acceleration due to gravity = 9.8 ms-2 downwards.

Remember that g could be negative, depending on the frame of reference

Page 11: Do Now A motorbike accelerates at 2.6 ms -2 for 4 seconds until it reaches the new speed of 25 ms -1. a)What distance is covered along the course of acceleration?

Question THREE

Hayden throws his cricket ball perfectly vertically upwards. The ball takes 2.3 seconds to reach its maximum height, then it falls back down.

a) How high does the ball travel up? (ignore Hayden’s height)

b) What is the initial speed of Hayden’s throw?