Calculate a constant force required to bring an object of mass 2.0kg.moving with a velocity of 4.0m/s to rest in. 0.1sec and 2metre

Answer 1

a=changevelociy/time= (0-4)/.1=-40m/s^2
force=mass*acceleration=80N

Answer 2

you can have 0.1 s OR 2 m...not both (unless it is two different scenarios)

stopping in 0.1 s means traveling 0.2 m ... as bob said , 80 N

stopping in 2 m takes 1.0 s ... 8 n

Answer 3

V = Vo + a*t = 0,
4 + a*0.1 = 0,
a = -40 m/s^2.

F = M*a = 2 * (-40) = -80 N. The negative sign means the force
opposes the motion.