MHB Physics problem of Man standing in a truckbed

[leprofece]

A man is standing on the platform of a truck moving at 36 km/hr, in what angle and in what direction the man should the man stand to avoid falling if, in 2 seconds the speed of the truck changes to:
(a) 9 km/hr?
(b) 45 km/hr ?

 

[jedishrfu]

We must have a caveat here that no one should try this problem at home by standing in a moving truckbed as sudden unexpected accelerations of decelerations of the truck can launch you into the air with disastrous consequences when you hit the ground.