I trust FF got q1 and 2 right so ill do some. Ill start from the end as thats the ones most people want.
10(a) (i) dv/dt = k so dv = k dt for some constant k. Integrating both sides gives v = kt + c
1
(ii) Integrate v = kt + c
1 to get x. x = 1/2(kt
2) + c
1t + c
2
When t = 0, x = 1 so 1 = 0 + 0 + c
2 and hence c
2 = 1
When t = 1, x = 2 so 2 = 1/2k + c
1 + 1 which gives k + 2c
1 = 2
When t = 2, x = 9 so 9 = 2k + 2c
1 + 1 which gives 2k + 2c
1 = 8
k + 2c
1 = 2
2k + 2c
1 = 8
Subtract one from the other gives k = 6 and sub back in gives c
1 = -2
Hence x = 3t
2 - 2t + 1
(iii) v = kt + c
1 but we know k and c
1 which gives v = 6t - 2
Particle comes to rest when v = 0, ie. when 6t - 2 = 0 and t = 3 seconds.
10 (b) (i) (Note: alpha = A and beta = B)
In triangle ACD, cosB = CD/AC = h/b so h = bcosB
In triangle BCD, cosA = CD/BC = h/a so h = acosA
Hence h = bcosB = acosA
(ii) General area of a triangle formula: A = 1/2absinC
In triangle ACD, Area = 1/2*AC*CD*sinB = 1/2*b*h*sinB = 1/2absinBcosA (since h = acosA from (i))
(iii) Area = 1/2*CD*BC*sinA = 1/2ahsinA = 1/2absinAcosB (since h = bcosB)
(iv) Area = 1/2*AC*BC*sin@ (where @ = angle ABC) = 1/2absin(A + B)
(v) Area (ABC) = Area (ACD) + Area (BCD)
1/2absin(A + B) = 1/2absinBcosA + 1/2absinAcosB
You can divide by 1/2ab
so sin(A + B) = sinBcosA + sinAcosB
I just went through this quickly, please tell me if I made any errors. Ill try do some of the others when I get back. If anyone else wants to try some the link to the paper is here:
http://www.boredofstudies.org/mirror/2004/2004_Maths2u_T_CSSA_q.pdf