• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Physics: Post your doubts here!

tawab

tawab

Messages
25
Reaction score
5
Points
13
plz provde the answers of the compiled p1 questions

pzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
 
hussamh10

hussamh10

Messages
210
Reaction score
38
Points
38
plz can anyone help me with practicle in question no 2 when it asks about that compare the relationship or what is the relation ship where we have to fin the values of K and how you determined the sig figure how do you do that????
 
emkay

emkay

Messages
259
Reaction score
162
Points
53
hussamh10 said:
plz can anyone help me with practicle in question no 2 when it asks about that compare the relationship or what is the relation ship where we have to fin the values of K and how you determined the sig figure how do you do that????
Click to expand...
once you've calculated the two different values of k, find their percentage and if the result is greater than 80% say it is valid or your calculations support the suggested relationship. i.e k1=25 and k2=56 use, 25/56*100 which gives 45%. that means the calculations does not support the result (as 45% is less than 80%)
 
KurayamiKimmi

KurayamiKimmi

Messages
191
Reaction score
80
Points
38
can someone solve this question please :/

A metal bob of 0,25 kg is suspended from a string of length 0.40 m .It is pulled up in such a way that is centre of mass is rises by 20cm above its mean position.
Find the maximum tension in the string .
 
M

Meo

Messages
29
Reaction score
5
Points
13
Silent Hunter said:
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s04_qp_1.pdf


Questions : 16,25,33
Click to expand...

I'm not good at explaining things but I'll try my best.

for 16.
A. The kinetic energy of the ball is greatest at the greatest height attained.
This is not true because, at the greatest height, the velocity is 0 therefore the kinetic energy is 0.

B. By principle of conservation of energy, the total energy of the ball is constant throughout the motion.
I think this is correct, because there is no energy loss throughout this motion. (i.e. no work against air resistance.)

C. By principle of conservation of momentum, the momentum of the ball is constant throughout the motion.
Wrong, because momentum is the product of mass and velocity, and you should know that throughout the motion, the velocity is not constant. There is acceleration. (9.81/-9.81 depending from where you at it)

D. The potential energy of the ball increases uniformly with time during the ascent.
The keyword to this option is 'uniformly'. It's true the fact that as you move upwards, the gravitational potential energy increases. BUT it will increase uniformly if and only if it moves upwards with uniform velocity. But again, you have acceleration.

So the answer is B.

I'm not quite sure about 25, sorry, but for 33, the answer is C because the fall in voltage is due to the existing PD across the internal resistance and to calculate for this PD (fall in voltage).
V=IR
you will need the current and the resistance.
 
Silent Hunter

Silent Hunter

Messages
4,609
Reaction score
3,903
Points
323
Meo said:
I'm not good at explaining things but I'll try my best.

for 16.
A. The kinetic energy of the ball is greatest at the greatest height attained.
This is not true because, at the greatest height, the velocity is 0 therefore the kinetic energy is 0.

B. By principle of conservation of energy, the total energy of the ball is constant throughout the motion.
I think this is correct, because there is no energy loss throughout this motion. (i.e. no work against air resistance.)

C. By principle of conservation of momentum, the momentum of the ball is constant throughout the motion.
Wrong, because momentum is the product of mass and velocity, and you should know that throughout the motion, the velocity is not constant. There is acceleration. (9.81/-9.81 depending from where you at it)

D. The potential energy of the ball increases uniformly with time during the ascent.
The keyword to this option is 'uniformly'. It's true the fact that as you move upwards, the gravitational potential energy increases. BUT it will increase uniformly if and only if it moves upwards with uniform velocity. But again, you have acceleration.

So the answer is B.

I'm not quite sure about 25, sorry, but for 33, the answer is C because the fall in voltage is due to the existing PD across the internal resistance and to calculate for this PD (fall in voltage).
V=IR
you will need the current and the resistance.
Click to expand...

i appreciate your answer

thank you
 
hussamh10

hussamh10

Messages
210
Reaction score
38
Points
38
emkay said:
once you've calculated the two different values of k, find their percentage and if the result is greater than 80% say it is valid or your calculations support the suggested relationship. i.e k1=25 and k2=56 use, 25/56*100 which gives 45%. that means the calculations does not support the result (as 45% is less than 80%)
Click to expand...
Wanted to ask another thing that if in Q2 for example it asks to time when ball travels from Mark A to Mark B in a bottle full of water when we time it we must take two readings then what will be the absolute error we should take to calculate % error.
 
DumbIdiot

DumbIdiot

Messages
158
Reaction score
55
Points
38
what does this mean - "testing against a criterion specified by the candidate"
it is in most of the practical papers where we need to say whether the suggested relationship is right
 
R

raamish

Messages
373
Reaction score
33
Points
28
Physics A2 radioactivity question:
No= 1* 10^15
decay constant= 0.02 s-1
t= 20 s

N=No e (-d.c* t)
how do we use the ex in calculator in this question? ty
 
You must log in or register to reply here.
Top