a box of a mass $2\mathrm{.}2$kg moves along the x axis on a frictionless floor. it is being pushed by a force F at the angle theta $=22.$ below horizon $($see figure$)$ The postion of the bo x at time t is guven as x$=42$t$^4+4\mathrm{.}4$t$^2,$ where t is in s and x in m part $($a $)$ what is the acceleration of the box at t$=\mathrm{.}15$s part $(b)$ what $is$ the magnitude $of$ the pushing force $t=\mathrm{.}15s$