Question

A truck of mass 2000 kg moving on a highway experiences an average frictional force
of 800 N. If its speed increases from 25 ms −1 to 35 ms −1 over a distance of 500 m,
what is the force generated by the truck.

Answer 1

Given ;
u = 25m/s
v = 35m/s
S = 500 m

v^2 - u^2 = 2aS
(35×35) - (25×25) = 2×a×500
1225-625 = 1000a
a = 600/1000
a = 6/10
a = 0.6 m/s^2

Force generated by the truck
= ma + frictional force
= 2000 × 0.6 + 800
= 2000 N
____________________

Answer 2

given
m=2000kg
f=800N
s=500m
v=35
u=25
here by using the formula
v^2=u^2+2as
(35)^2=(25)^2+2*a*500
1225=625+1000a
therefore
1000a =1225-625
a=600/1000=0.6m/s^2.
the force generate by the truck is 2000*0.6+800=2000N