4.53 cntc The position ofa 2.75 x 105N training helicopter under test is given by i3 = (0.020 m/53)r3i + (2.2 m/s)rj (0.060 m/szhzlit. Find the net force on the helicopter at! = 5.0 s. 4.59 EMC An object with mass m moves along the .r-axis. Its position as a function of time is given by .r(r) = A! 3:3. where A and B are constants. Calculate the net force on the object as a function of time. 4.50 BALE An object with mass m initially at rest is acted on by a force F" = k1? + 1639}, where k] and k2 are constants. Calculate the velocity 30') of the object as a function of time