Four red flags
The load being carried poses a hazard to vehicles in the proximity of the load-carrying vehicle, and so it is mandatory by law for the vehicle to make the load more visible. At night time, the load is marked using red lights, as flags would not be visible then.
Explanation:
The angle of the handle relative to the horizontal is 35°. The angle of the ramp to the horizontal is 7°. So the angle of the handle relative to the ramp is 28°.
cos 28° = 50 / F
F = 50 / cos 28°
F = 56.6 lbs
Second question: tensional stress causes fractures to occur in the lithosphere.