--- Integral Variable Acceleration Topic - Assessment Answers

(b) ( s(t) = \int (\sin 2t + \cos t) dt = -\frac{1}{2}\cos 2t + \sin t + D ) ( s(0) = -\frac12(1) + 0 + D = -\frac12 + D = 0 \Rightarrow D = \frac12 ) [ s(t) = -\frac12\cos 2t + \sin t + \frac12 ] (a) ( v(t) = \int (12t^2 - 8t + 2) dt = 4t^3 - 4t^2 + 2t + C ) ( v(1) = 4 - 4 + 2 + C = 2 + C = 5 \Rightarrow C = 3 ) [ v(t) = 4t^3 - 4t^2 + 2t + 3 ]

(b) ( v(t) = 0 \Rightarrow \frac{t^2}{2}\left(3 - \frac{t}{3}\right) = 0 ) ( t = 0 ) or ( t = 9 ) seconds (answer: ( t = 9 )) --- Integral Variable Acceleration Topic Assessment Answers

(b) ( s(t) = \int \left(6 - \frac{4}{t+1}\right) dt = 6t - 4\ln(t+1) + D ) ( s(0) = 0 - 0 + D = 0 \Rightarrow D = 0 ) [ s(t) = 6t - 4\ln(t+1) ] (a) ( v(t) = \int 12 t^{1/2} dt = 12 \cdot \frac{2}{3} t^{3/2} + C = 8 t^{3/2} + C ) ( v(4) = 8 \cdot 8 + C = 64 + C = 10 \Rightarrow C = -54 ) [ v(t) = 8t^{3/2} - 54 ] (b) ( s(t) = \int (\sin 2t +

(c) ( s(t) = \int v(t) dt = \frac{t^3}{2} - \frac{t^4}{24} + D ), ( s(0) = 0 \Rightarrow D = 0 ) Distance ( = s(9) = \frac{729}{2} - \frac{6561}{24} ) ( = 364.5 - 273.375 = 91.125 \ \text{m} ) (or ( \frac{729}{8} \ \text{m} )) (a) ( v(t) = \int (2\cos 2t - \sin t) dt = \sin 2t + \cos t + C ) ( v(0) = 0 + 1 + C = 1 \Rightarrow C = 0 ) [ v(t) = \sin 2t + \cos t ] --- Integral Variable Acceleration Topic Assessment Answers