Thank you so mu rl.bhat.
After the 2nd derivative I get a= (.12m/s^3)(t) - .12m/s^2
= (.6m/s^2)- .12m/s^2= -.6 m/s^2
F=m*a m=F/a m=3000n/9.81m/s^2=305.8kg
m*a=F 305.8 kg * -.6m/s^2=-183.48N Is that thought process correct?
[b]1.The position vector of a 3000N helicopter is given by:
r=(.02 m/(s^3))(t^3)i + (2.2m/s)tj - (0.06 m/(s^2))(t^2)k
Find the net force on the helicopter at t = 5s.
[b]2. I really have no clue where to begin.
[b]3. I started doing this:
r=...