The relationship between the displacement travelled by a body and the time t is described by the equation `s = A + Bt + Ct^(2) + Dt^(3)`. Where `C = 0.14m//s^(2)` and `D=0.01m//s^(3)`. In what time after motion begins will the acceleration of the body be equal to `1 m//s^(2)?`

Options

A. 10 sec
B. `50 // 3 "sec"`
C. 12 sec
D. 18 sec

Answer

C

Explanation

`S=A+Bt+Ct^(2)+Dt^(3)`
`V=B+2Ct+3Dt^(2)`
`a=2C+6Dt`
`1=2xx0.14+6xx0.01t`
t = 12 sec