A 24 tonne semi-trailer is travelling up a hill with gradient 8 degrees at a speed of 70 kph. It has a frontal area of 5 square meters and the coefficients of rolling resistance and drag are 0.015 and 0.8, respectively. Assuming air density is 1.25 kg/m3 and gravitational acceleration is 9.8 m/s2, what tractive effort (in kN to 1 decimal place) is required to keep the semi-trailer at a constant 70 kph up the hill