AQA Physics A Unit 2 - 4th June 2015 (PM)

Original post by a.a.k

Yiu always use suvat
Its just the case if a=0 then 0.5at^2 bexomes zero so equarion s=ut+0.5at^2 becomes s=vt and so on.
Just right down list of
S
U
V
A
T

And then put the values you have git and find the missing

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https://21ba06f4363c89790b62ca84c35719fd50682758.googledrive.com/host/0B1ZiqBksUHNYZllpVTRUcDhQUmM/From-AQA-Set-B/2.1.4%20Projectiles.pdf

what about page 5 the darts question on time, how would i use suvat?

Reply 583

theoriginalrpr

1

Original post by JM17

Can you answer WMP/Jan12/PHY2 Question 7(b) then?

http://filestore.aqa.org.uk/subjects/AQA-PHYA2-QP-JAN12.PDF

This is not a stationary wave.

The knot is moving in the opposite direction to the way in which the wave is travelling so going down and then up. x

Original post by liverpool2044

https://21ba06f4363c89790b62ca84c35719fd50682758.googledrive.com/host/0B1ZiqBksUHNYZllpVTRUcDhQUmM/From-AQA-Set-B/2.1.4%20Projectiles.pdf

what about page 5 the darts question on time, how would i use suvat?

This question concerns projectile motion. S=ut+1/2at^2 is used here for vertical and horizontal motion. In the vertical sense, the initial velocity, u, is zero and hence s=1/2at^2. In the horizontal sense there is no acceleration (there is no resistance to motion, hence this is why this can be deduced) So a=0 and thus S=ut.

Reply 588

Original post by liverpool2044

https://21ba06f4363c89790b62ca84c35719fd50682758.googledrive.com/host/0B1ZiqBksUHNYZllpVTRUcDhQUmM/From-AQA-Set-B/2.1.4%20Projectiles.pdf

what about page 5 the darts question on time, how would i use suvat?

They are rekeased at the same instant but horizontal accel of dart is zero.
The accel at the same rste 9.8 so the would take same time to hit the ground

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Reply 589

Since a=0 use s=ut

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Reply 590

Original post by Protoxylic

This question concerns projectile motion. S=ut+1/2at^2 is used here for vertical and horizontal motion. In the vertical sense, the initial velocity, u, is zero and hence s=1/2at^2. In the horizontal sense there is no acceleration (there is no resistance to motion, hence this is why this can be deduced) So a=0 and thus S=ut.

Ah great thanks

Reply 591

JM17

3

Original post by theoriginalrpr

It's a transverse wave, therefore the vibrations travel perpendicular to the direction of travel of the wave. That's why it moves UP/DOWN only. However, in this case, the reason it moved DOWNWARDS is because the wave was travelling to the right and the trough passes through it first.

Original post by theoriginalrpr

The knot itself is actually stationary. As the wave is moving --> in that direction by default the not will have appeared to have moved whereas it is just the wave moving

Click. Got it.

Many thanks/

Reply 592

Original post by a.a.k

Since a=0 use s=ut

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How do you know its a = 0?

Reply 593

theoriginalrpr

1

Original post by JM17

Click. Got it.

Many thanks/

Anytime

Reply 594

Original post by liverpool2044

How do you know its a = 0?

For horizontal motion there is no force to resist ( assuming air resistance is neglible) and there is no force pushing it in horizontal component so 0 resultant force horizintally

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Reply 595

theoriginalrpr

1

Original post by liverpool2044

How do you know its a = 0?

split up into horizontal and vertical components...
For PART 4BI) Horizontal use S=D/T
For PART 4BII) vertical use S=UT+0.5GT SQUARED (Solve for u)

For projectiles always split components into horizontal and vertical.
Horizontal is always speed=distance over time
Vertical - use one of the suvat equations but always use g instead of a

Reply 596

Original post by a.a.k

For horizontal motion there is no force to resist ( assuming air resistance is neglible) and there is no force pushing it in horizontal component so 0 resultant force horizintally

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thank you so force is needed for acceleration in horizontal

Reply 597