2012 t2 exam paper 1 and 2 answers

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  • 7/28/2019 2012 T2 Exam Paper 1 and 2 Answers

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    May 2012. Term Two Physics AS examination. MC answers.1 A 21 C2 C 22 C3 C 23 C4 B 24 C

    5 D 25 C6 C 26 B7 B 27 A8 A 28 C9 B 29 B10 C 30 B11 C 31 A12 A 32 C13 C 33 D14 A

    15 D16 B17 A18 C19 D

    20 A

    1. (a) (i)

    F1 weight /mg(1)

    F2 reaction or normal contact force(1)

    F3 driving force(1)

    F4 friction or air resistance(1)

    (ii) zero acceleration (1)

    zero resultant force(1) max 5

    (b) (P =Fvgives) 18 103 =F 10(1) (andF =1.8 103 N) 1

    (c) (i) 1800 250 =1.6 103 N (1) (1.55 103 N)

    (ii) force =4 1.55 103 =6.2 103 N (1)(allow e.c.f. from(i))

    (iii) total force =6200 +250(N) (1) (=6.45 103(N))

    (P =Fvgives) P =6.45 103 20 =1.3 105 W (1) (1.29 105 W)(allow e.c.f. for value of total force) 4 [10]

    2. (a) scalars havemagnitude(or size) (1)vectors havemagnitudeanddirection(1) 2

  • 7/28/2019 2012 T2 Exam Paper 1 and 2 Answers

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    (b) (i) s=t(1)

    s=100 =5 km(1)

    (ii) 1.59 (1) km (or other correct unit) (1) 4[6]

    3. (a) 2

    (b) (i) taking moments (about A) (1)(400 4.0) +(300 2) =FB 1.6(1)

    =FB soFB =1375(N) (1)

    (ii) FA =1375 700 =675 (1) N (1) allow e.c.f. fromFB

    (no marks if weight of board not used) max 4[6]

    4. accept mirror image for (a) and (b)

    (a) (b)

    straight line sloping up (1) constant value shown(1)sudden change to negative velocity (1)smaller negative velocity (1)same gradient as positive line(1) 4

    (c) (i) vertically down at P (1) (ii) vertically down at Q (1)

    (iii) along tangent at P (1) (iv) along tangent at Q (1) 4

    (d) horizontal component of velocity at Q = 15 cos 50(1) =9.64 m s1(1)

    momentum at Q =0.15 9.64 =1.45 (1) Ns (or kg m s1) (horizontally) (1) 4[13]

    60

    3

    F

    F

    A

    B(1)

    (1)

    6.1

    2200

    velocity

    time

    acceleration

    time

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    5. (a) (i)

    B must make an appreciable angle with wall and bar

    (ii) A weight of sign and bar (accept gravity) (1)B reaction of wall (1)C tension in wire(1) max 5

    (b)

    use ofmg(1) clockwise moments 118 0.375 (1)

    =anticlockwise moments (Tcos40 (1)) 0.750(1) T=77 N (1) max 4[9]

    6. (a) (i) equation showing momentum before =momentum after (1)

    correct use of sign(1)

    (ii) no external forces (on any system of colliding bodies) (1) 3

    (b) (i) (by conservation of momentumm11 +m22 =0)

    0.25 2.2 =()0.502(1)

    2 =()1.1(0)msl(1)

    (ii) =total k.e. = 0.25 2.22 + 0.5 1.12(1)

    =0.91J (1) 4 [7]

    7. (a) (i) gradient = =3.0 ms2(1)

    (ii) distance is area under graph (to t=0.1 s)

    or 0.7 2.1 0.3 (1) =1.4(2) m(1) 3

    (b) (i) T mg=ma [orT=1500(9.8+3.0)] (1)

    =1.9 104 N (1)

    T=mg=l.5 104N (1)

    (ii) EF (1) 4

    (c) power =F or l.5 1042.5(1) =3.7[3.8] 104 W (1) 2[9]

    B

    C

    A

    (1)

    (1)

    (1)

    0.375m

    118N

    40

    2

    1

    2

    1

    7.0

    1.2

    2

    1

    +

    2

    5.21.2

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    8. (i) a= =11 ms2(1) F =ma=1.1 105 N (1) (ii) =236 m s1

    a= =29.5 ms2(1)(iii) sone= t= 4.0 =88m(1)

    stwo = t= 8.0(1) =1296(m) (1) total distance =1384 m(1)

    [6]

    9. (a) sum of clockwise moments equals sum of anticlockwise moments(1)for a body in equilibrium(1) 2

    (b) point in the body through which the weight/mass (appears to) acts[or point where resultant torque/moment is zero]

    [or point where body would balance] (1) 1

    (c) (i) towards A (1)so that weight of ruler (1)provides balancing moment (1)

    (ii) (moments about pivot give) 1.0 (0.30 d) =0.50 d(1)1.5d=0.30 andd=0.20 m(1) 5

    [8]

    10. (a) (i) (use ofv2 =u2 +2asgives) 0 =252 - 2 9.81 s(1)19.6s=625 ands=32 m(1)

    (ii) t= =2.5 s(1)

    (iii) (use ofv2 =u2 +2asgives) v2 =252 2 9.81 16(1)

    (allow C.E. from (a)(i)) andv=18 m s1(1) max 4

    (b) time to stop the ball is greater (1) rate of change of momentum is less(1)

    [or work done on ball is the same but greater distance(1) less force(1) ] 2[6]

    11. (a) kinetic energy not conserved (1)[or velocity of approach is not equal to velocity of separation] 1

    (b) (i) (use ofp=mvgives) p=4.5 102

    60 (1)=2.7 kg m s1 (1)

    (ii) (use ofF = gives) F = (1)

    =180 N (1)

    [or a= = =4000 (ms1)

    F =(ma) =4.5 102 4000 =180 N] 4

    [5]

    0.4

    44

    0.8

    236

    av

    +

    2

    044

    av

    +

    2

    44280

    81.9

    25

    t

    mv

    )(31015

    7.2

    t

    uv31015

    60