The position of a 2.75×105N training helicopter under test is given by r⃗ =(0.020m/s3)t3i^+(2.2m/s)tj^−(0.060 m/s2)t2k^.

Find the net force on the helicopter at t=5.0s.

Express your answer in terms of i^, j^, k^. Use the 'unit vector' button to denote unit vectors in your answer. Express your coefficient using two significant figures.