Answer to Question #69372 in Mechanics | Relativity for Lilly

Question

An object of mass 5835 kg rests on the flatbed of a truck. It is held in place by metal
brackets that can exert a maximum horizontal force of 9120 N. When the truck is
traveling 28 m/s, what is the minimum stopping time if the load is not to slide forward
into the cab?

Answer 1

When truck is slowing down, an object tries to save his velocity. But it slows with acceleration which leads to the force from the metal brackets that acts on an object. Due to the second Newton`s law:
F=ma.
Also it`s obvious that
v=at.
Combining these formulas, we obtain that the maximum force corresponds to the minimum time:
t_min=vm/F_max =(28 m/s 5835 kg)/(9120 N)≈17.9 s
Answer: 17.9 s