During the launch, the person was accelerating against the
gravity, therefore the equation we use in this case is:
F = m * (g + a)
where m is mass = 60 kg, g is gravity = 9.81 m/s^2, a is
acceleration = 4 * g
therefore:
F = m * (g + 4 g)
F = m * 5 g
F = 60 kg * 5 * (9.81 m/s^2)
F = 2943 N
