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National 5 Physics 2015-2016

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Reply 20
Avatar for M.U.A
M.U.A
1
The gravatational field strength of the point which the ball is in is 1.225J. This is due to the fact it is o.25 m above the ground this, substitute this in the formula e=mgh and you would get 1.225J. The kinetic energy is the conversation of the gravitational energy lost during its flight down 0.75m so, substituting 0.75m as a height in e=mgh will get you the kinetic energy, hope this helps. For question 8 since it is milliseconds, concerts this into seconds so divide 8 by 1000 and then substitute it into the frequency formula, so it will be like 1/8 divided by 1000, giving 125. Remember to always convert any figure into its unit i.e nano amps to amps.
Reply 21
Avatar for M.U.A
M.U.A
1
Do any of you know good past paper questions for revision, it my will be helpful. Also anyway physics question booklets also. Thanks
Original post by M.U.A
The gravatational field strength of the point which the ball is in is 1.225J. This is due to the fact it is o.25 m above the ground this, substitute this in the formula e=mgh and you would get 1.225J. The kinetic energy is the conversation of the gravitational energy lost during its flight down 0.75m so, substituting 0.75m as a height in e=mgh will get you the kinetic energy, hope this helps. For question 8 since it is milliseconds, concerts this into seconds so divide 8 by 1000 and then substitute it into the frequency formula, so it will be like 1/8 divided by 1000, giving 125. Remember to always convert any figure into its unit i.e nano amps to amps.


That is very helpful!
Reply 23
Avatar for M.U.A
M.U.A
1
Your welcome
Original post by M.U.A
The gravatational field strength of the point which the ball is in is 1.225J. This is due to the fact it is o.25 m above the ground this, substitute this in the formula e=mgh and you would get 1.225J. The kinetic energy is the conversation of the gravitational energy lost during its flight down 0.75m so, substituting 0.75m as a height in e=mgh will get you the kinetic energy, hope this helps. For question 8 since it is milliseconds, concerts this into seconds so divide 8 by 1000 and then substitute it into the frequency formula, so it will be like 1/8 divided by 1000, giving 125. Remember to always convert any figure into its unit i.e nano amps to amps.


Okay thank you so so much! One last question though when measuring the Gravitational Field Strength using mgh, why do you use 0.25 and not 0.75? This is the part that's getting me confused if you could explain that then that would be very helpful.

Oh right yes, thanks for helping the last question too I totally forgot about conversions
Original post by sameehaiqbal
Okay thank you so so much! One last question though when measuring the Gravitational Field Strength using mgh, why do you use 0.25 and not 0.75? This is the part that's getting me confused if you could explain that then that would be very helpful.

Oh right yes, thanks for helping the last question too I totally forgot about conversions


Im the opposite of you, I don't understand why 0.75m used as the hight for the Kinetic energy,
Hope somebody can help out ASAP!
Reply 27
Avatar for M.U.A
M.U.A
1
By the principle conservation of energy " energy cannot be created nor destroyed but can be changed from one form to another", the 0.75 m above is what the ball travelled while its way down. This energy is the kinetic energy. You would use this figure in the formula e=mgh as all ( well most) is turned into kinetic energy thus calculating the gravitational field strengtth of the 0.75m will give you the kinetic energy of the ball, as it has converted from gravatational field strength energy to kinetic energy. 😊
Reply 28
Avatar for M.U.A
M.U.A
1
Original post by sameehaiqbal
Okay thank you so so much! One last question though when measuring the Gravitational Field Strength using mgh, why do you use 0.25 and not 0.75? This is the part that's getting me confused if you could explain that then that would be very helpful.

Oh right yes, thanks for helping the last question too I totally forgot about conversions

As at it is at a height of 0.25m, as the other 0.75 is converted to kinetic energy
Original post by M.U.A
By the principle conservation of energy " energy cannot be created nor destroyed but can be changed from one form to another", the 0.75 m above is what the ball travelled while its way down. This energy is the kinetic energy. You would use this figure in the formula e=mgh as all ( well most) is turned into kinetic energy thus calculating the gravitational field strengtth of the 0.75m will give you the kinetic energy of the ball, as it has converted from gravatational field strength energy to kinetic energy. 😊


Thanks so much :smile:

I have another question, I noticed you are using E =mgh for both Kinetic and Potential energy.

I was taught to calculate Potential Energy you would use Ep=mgh
and to calculate Kinetic Energy you would use Ek=1/2mv^2

Am I wrong ? Are you allowed to you any equation for any energy ?

Thank you
Thank you!!! That was an A grade questiom btw. BTW @M.U.A please stick around the thread for the next week because i need some smart people to help me theoughout my revision LOL 😂
Original post by sameehaiqbal
Thank you!!! That was an A grade questiom btw. BTW @M.U.A please stick around the thread for the next week because i need some smart people to help me theoughout my revision LOL 😂


Yeah, hahah so truee,

I am estimated for an A and I really want to get it :P
Is @M.U.A doing Nat 5? He seems a lot more advanced than that
What are peoples predictions on the open ended question? Those are the ones I struggle with the most, got any tips or advice for it? :frown:
I think it will be some type of cosmology question from the Unit Dynamics and Space
Original post by Ethan100
I think it will be some type of cosmology question from the Unit Dynamics and Space


Hmm they already used one from Dynamics and Space though about space exploration. I really hope it's on Nuclear Radiation because I can write a lot on that!!
Original post by sameehaiqbal
Hmm they already used one from Dynamics and Space though about space exploration. I really hope it's on Nuclear Radiation because I can write a lot on that!!


Yeah thats a good point, What would they ask about Nuclear Radiation though
Original post by Ethan100
Yeah thats a good point, What would they ask about Nuclear Radiation though


Maybe why Alpha, Beta, Gamma can only penetrate through certain things, what atoms they are made of and how ionizing certain radiation is. They might give an example of an industrial scenario of Radiation and ask us to explain about radiation and what they are able to penetrate, absorb, and how much energy they have. This is my prediction but i'm not sure
Is there normally two open ended questions?
Original post by sameehaiqbal
Is there normally two open ended questions?


Well that's what I had in my prelim so Im guessing so
Reply 39
Avatar for Jay431
Jay431
2
Original post by sameehaiqbal
Is there normally two open ended questions?


Maximum two open ended questions.

I have a feeling they'll give us something about Pressure and then Nuclear Radiation

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