HSC Physics Question Thread

[mxrylyn]

Is there a linear relationship between the Period and Length of the pendulum, and a parabolic relationship between the period squared and the length of a pendulum?

These are the results I found from a first hand investigation

[jakesilove]

Is there a linear relationship between the Period and Length of the pendulum, and a parabolic relationship between the period squared and the length of a pendulum?

These are the results I found from a first hand investigation

Hey!

The mathematical relationship describing the pendulum's motion is



Where T is the period, l is the length of the string and g is the acceleration due to gravity.

So, you shouldn't be getting a linear relationship when plotting T against l; the equation is more complication than that. However, if you square both sides;



and plot T squared against l, then you should get a linear plot. So, is it possible you've just written your results the wrong way around?

Jake

[mxrylyn]

Hey!

The mathematical relationship describing the pendulum's motion is



Where T is the period, l is the length of the string and g is the acceleration due to gravity.

So, you shouldn't be getting a linear relationship when plotting T against l; the equation is more complication than that. However, if you square both sides;



and plot T squared against l, then you should get a linear plot. So, is it possible you've just written your results the wrong way around?

Jake

YES! THANK YOU!

[itssona]

any help on this question please
An astronaut travelling at 0.5c takes 10 hours ship time to reach her destination. Calculate how much time has passed on Earth as measured by:
(a) an observer on earth
(b) the astronaut

so I did part a) since I figured I need to find out Tv and my answer was 11.55 hours which is correct buuuuut how to do b? the answer is 8.7 hours but how

thank you

[KiNSKi01]

so I did part a) since I figured I need to find out Tv and my answer was 11.55 hours which is correct buuuuut how to do b? the answer is 8.7 hours but how

thank you

The astronaut would observe time to be running slow for earth so all you have to do is divide 10 hours by what you used for gamma in the previous question 

[itssona]

The astronaut would observe time to be running slow for earth so all you have to do is divide 10 hours by what you used for gamma in the previous question 

Gamma??

[RuiAce]

Gamma??

Having said that

The astronaut would observe time to be running slow for earth so all you have to do is divide 10 hours by what you used for gamma in the previous question 

Please keep in mind that in the HSC, they aren't taught the specific terminology of the Lorenz factor. The formulas involving relativity automatically substitute \(\frac{1}{\sqrt{1-v^2/c^2}} \) straight in

[itssona]

Having said thatPlease keep in mind that in the HSC, they aren't taught the specific terminology of the Lorenz factor. The formulas involving relativity automatically substitute \(\frac{1}{\sqrt{1-v^2/c^2}} \) straight in

ohhhh thank you both

[itssona]

also this one
Alpha centauri is 4.5 light years away from earth. Imagine a spaceship able to fly at 0.9c. How long would it take to get there as observed by its pilot, and by mission control on Earth?

so I got that the time for astronaut is Tv which is 2.16 years but how do I find how long it takes as observed by mission control on earth?

my values are v = T_v= 2.16 T_0=0.5c

kinda confused

thank you

[yum.z2]

Hi guys,

for a physics assignment the questions are : the scientist is VON BRAUN
-Outline the contribution of the chosen scientist towards rocket development and link how the disocveries are important in making rocket development possible
-Describe the impact of their discovery to advancement of modern rocketry


need helppp

[Mate2425]

Hi can i get some help with this question please... What is the acceleration due to gravity on a moon of mass 1.67×10^18 Kg and has a diameter of 4765km.

Thanks.

[justwannawish]

Hey guys, some questions about inertial frames of reference
If a bus accelerates to the right, which way would a person have to lean to prevent falling? I think it's right? but don't get why
which way would the direction of gravity seem to be?
And if you dropped something, which direction would it go?

[Natasha.97]

Hey guys, some questions about inertial frames of reference
If a bus accelerates to the right, which way would a person have to lean to prevent falling? I think it's right? but don't get why
which way would the direction of gravity seem to be?
And if you dropped something, which direction would it go?

Hi!

Disclaimer: Don’t do Physics so I’m not 100% sure if this is correct:

The way I think about it is the person is still “stuck” in the original position and wants to remain there until they purposely move. Hence, the person leans to the right to avoid falling towards their original position (which is towards the left). If they dropped something, the same logic applies that it will fall towards the left. Think about it this way: if the bus you were on was accelerating and suddenly stopped at a red traffic light, you’ll lean backwards to prevent falling forwards.
Hope this helps

[jamonwindeyer]

Hi can i get some help with this question please... What is the acceleration due to gravity on a moon of mass 1.67×10^18 Kg and has a diameter of 4765km.

Thanks.

Hey! Link \(F=mg\) to universal law of gravitation, and you'll see stuff cancel:



You have these values! \(M\) is the mass of the moon and \(d\) is the radius of the moon (cut the diameter in half) - Remember to convert to SI units!

[Mate2425]

Thanks Jamon 

Hey! Link \(F=mg\) to universal law of gravitation, and you'll see stuff cancel:



You have these values! \(M\) is the mass of the moon and \(d\) is the radius of the moon (cut the diameter in half) - Remember to convert to SI units!