Question

A car of mass 800kg is moving with a constant velocity 40km per h find the net force on it

Answer 1

$f = ma \\ a = \frac{dv}{dt} = \frac{40 \times 1000}{3600} = 11.11 \frac{m}{ {s}^{2} } \\ m = 800 \times 9.81 = 7848 \: newton \\ f = 7848 \times 11.11 = 87191.28 \: newton$