Question

A tractor of mass 2000kg pulls a trailer of mass 1500kg. The total frictional force is 3000N and acceleration of tractor and trailer is 3ms^-2 calculate:

a. The force exerted on the tractor by the tow bar when acceleration is 3ms^-2

b. The force exerted when did tractor and the trailer are moving on a constant speed of 4ms^-1

Answer 1

Given:

$M=2000\;\rm kg,\quad m=1500\: kg,$

$\\ F_f=3000\: {\rm N}.$

(a) $a=3\:\rm m/s^2,$

$$(M+m)a=F-F_f$$ $$F=(M+m)a+F_f\\=(2000+1500)*3+3000=13500\:\rm N$$

(b) $a=0,$

$$F=F_f=3000\:\rm N$$