Physics Predictions/Thoughts (1 Viewer)

scaryshark09

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For people who do physics, definitely including @scaryshark09 , do we need to know equation examples of alpha, beta and gamma decay off by heart? Can they ask us to give an example??
i would say it is best to learn these equations off by heart.
they can ask to give an example
 

skp_mp4

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How much yall reckon is gonna be good enough for a band 5 gonna be this year
 
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HELP PLEASE!
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Does anyone know how to solve these questions? They're from the 2023 parramatta high school trial paper
Below are their answers:










10: B
13: A
14: B
 

Aaryan123

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HELP PLEASE!
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Does anyone know how to solve these questions? They're from the 2023 parramatta high school trial paper
Below are their answers:










10: B
13: A
14: B

for q10, you want to find a general formula for the range of a projectile. range occurs when the y displacement =0.
so from s=ut+1/2at^2, you let s=0. you also know that you can divide by t, because that is at the origin, we're looking for the t when it hits the ground again.
therefore, 0=usintheta+(1/2)(-9.8)t
hence t=2usintheta/9.8
now the range is the horizontal component multiplied by time travelled
so Range = Utcostheta
= 2U^2sinthetacostheta/9.8
= (u^2)sin2theta/9.8
now sub in all values given in options, and B should be the largest.

13. Use kepler's 3rd law, and remember that the r value that you find is the radius of the earth plus the altitude.
14. Remember that during uniform circular motion, the value of the centripetal accel is v^2/r. both v^2 and r are constant in this example, so accel is also constant hence B
 

CamdenCeccato

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HELP PLEASE!
View attachment 41236

View attachment 41233
View attachment 41234
View attachment 41235

Does anyone know how to solve these questions? They're from the 2023 parramatta high school trial paper
Below are their answers:










10: B
13: A
14: B
There might be an easier way to do 10 but you calculate the time of flight for all the launches then find the range for all the launches.

i got d for 13 so I can’t help you with that one.
Don’t over complicate 14.
 
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There might be an easier way to do 10 but you calculate the time of flight for all the launches then find the range for all the launches.

i got d for 13 so I can’t help you with that one.
Don’t over complicate 14.
for q10, you want to find a general formula for the range of a projectile. range occurs when the y displacement =0.
so from s=ut+1/2at^2, you let s=0. you also know that you can divide by t, because that is at the origin, we're looking for the t when it hits the ground again.
therefore, 0=usintheta+(1/2)(-9.8)t
hence t=2usintheta/9.8
now the range is the horizontal component multiplied by time travelled
so Range = Utcostheta
= 2U^2sinthetacostheta/9.8
= (u^2)sin2theta/9.8
now sub in all values given in options, and B should be the largest.

13. Use kepler's 3rd law, and remember that the r value that you find is the radius of the earth plus the altitude.
14. Remember that during uniform circular motion, the value of the centripetal accel is v^2/r. both v^2 and r are constant in this example, so accel is also constant hence B
thank you for this !
 
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There might be an easier way to do 10 but you calculate the time of flight for all the launches then find the range for all the launches.

i got d for 13 so I can’t help you with that one.
Don’t over complicate 14.
you have to minus the radius of earth (6371km) from 6759.8, so 6759-6371km = 388.8 km and that's the answer
 

esybeast

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Can someone explain why the answer is D and not C? (question from PHS)
 

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