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HSC Physics Predictions / Thoughts (1 Viewer)

Luke322

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Yeah you used Grav force then just K = 1/2 m v^2 or something like that. Can’t remember specifically but there was hypothetically a second scenario where the planets are infinitely far away from one another and their speed cannot be determined. Not sure if that’ll be in the question though
oh thank god
 

Luke322

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I'm aiming for a 90 raw and I'm pretty sure I lost like 4 marks in multi's lol they were pretty hard (the last ones at least)
 

Luke322

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also what last minute stuff are u doing for chem?
 

Esdog07

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Q20 I put A in the exam
Here is my reasoning and my teacher's reasoning

The ball is projected at angle to horizontal and with speed u ms^-1. So it undergoes projectile motion. However it was projected against a circular wall. So it will also undergo circular motion. If you look at the image from the top you will see it undergo circular motion. If you look at the ball from in front of the wall, you will see it undergo projectile motion. So there is a force of gravity acting down on the ball, while there is a centripetal force acting on the ball that is perpendicular to the surface of the wall. We know that the centripetal force is dependent on the tangential velocity of the ball (which is the horizontal velocity of its projectile motion). The force of gravity is not dependent on the velocity of the ball, but it affects the vertical velocity of the projectile motion. So the horizontal velocity (tangential velocity) remains constant. So the centripetal force remains constant. We know that if a centripetal force acts perpendicular to the wall, and the gravitational force acts downwards, then centripetal force and gravitational force are always perpendicular. Hence the magnitude of the net force on the ball is constant.

PS. I also started to think about friction on the ball against the wall in the exam, but that made the thinking too complicated I reckon
 

Luke322

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what did you put for q19 (emf q) and 15 (trajectory one)
 
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For the motor pulling a mass I talked about factors influencing torque on the pulley (current, magnetic field strength, area and number of armature coils, etc

For the motor pulling a mass I talked about factors influencing torque on the pulley (current, magnetic field strength, area and number of armature coils, etc, and distance between rotor and pulley edge, as well as factors influencing friction on the mass I.e coefficient of friction and weight of the mass. For the standard model question I talked about how proton is a hadron + Baryon and how the electron is a lepton and examined the force carriers and their effects on the H atom.
how about back emf? could that be a point
 

Luke322

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Sure could be! I honest had so much to write about I ran out of room 😂 I mainly stuck with the essentials and a good in-depth explanation of net force linked to speed
my god so true I wrote like 4 pages for the 9 marker on bloody calculating energies and velocities
 

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