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Physics: Post your doubts here!

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dear all,
i need a suggestion and hope that u guys will suggest me the best,
i've got really unexpected result c in maths and d in chem and physics
i'm planning to appear for AS PHY this november and appear for chem accelerated in may/june 2016 as my teacher suggested so, before i appear for chemistry im going to get my papers rechecked because i dont think i can get less than an A.
plz give me your suggestion in this matter... SHOULD I APPEAR FOR PHY IN NOV OR NOT?
P.S. i was expecting STRAIGHT A's
 
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Calculate the energy needed to lift one kilogram from the surface of venus to a space station in orbit 900km from the surface
 
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A computer hard disk starts from rest, then speeds up with an angular acceleration of 190 rad/s^2 until it reaches its final angular speed of 7200 rpm.

How many revolutions has the disk made 10.0s after it starts up?
 
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it's a horizontal plane. i don't think this equation is correct
oh, you're right. I didn't see that. In that case Fc must be equal to Tension, so the formula F= mv^2/r (F= ma) should work.
F= 0.15 x 22.17 (acceleration calculated in b)
= 3.3264 N
 
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oh, you're right. I didn't see that. In that case Fc must be equal to Tension, so the formula F= mv^2/r (F= ma) should work.
F= 0.15 x 22.17 (acceleration calculated in b)
= 3.3264 N


I got the exact answer via a different method
I equated TSINtheta to Fc ( found in part b)
and Tcostheta to Weight
and found the resultant which was equal to the tension.

Thanks for helping though. :)
 
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I've been doing noticing in the MCQs lately that certain questions accept power=force x velocity
Whilst, yet other questions accept only power=work done/time taken.
 
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I got the exact answer via a different method
I equated TSINtheta to Fc ( found in part b)
and Tcostheta to Weight
and found the resultant which was equal to the tension.

Thanks for helping though. :)
Great! Had totally forgotten about that method.
 
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Aoa everyone. Can somebody please guide me to A2 topical worksheets? I mean question papers? It is difficult to check for a specific chapter in every paper.
 
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Hi
I just started my AS physics course 2 weeks ago and I have a quiz
I don't understand what's the difference between law of conservation of energy and work energy principle
 
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View attachment 56395

need help plz in this question
i) there will be a point in the field between the two, where Moon's gravitational field will cancel out earth's Gravitational field.

See, the resultant gravitational force on a test particle between the two will be equal to Fe (force by EARTH pulling the object towards its centre)- Fm (force by MOON pulling the object towards its centre). At some point, both will be EQUAL AND OPPOSITE. Hence, there would be 0 resultant force on the object!!

ii. Gravitational field will be zero when field by earth = field by moon

GMe/x2 = GMm/ (6ORe - x)^2 ; where Me and Mm are used to show mass of earth and moon respectively.
 
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