A force acts on an object of mass 1.5kg at rest for 0.5s. After the force stops acting the object travels a distance of 5m in 2s. hence the magnitude of the force will be?

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Answer 1 · 2017-07-04T16:03:23

#sumF_x = 7.5# #"N"#

We're asked to find the magnitude of the net force acting on the object.

We know:

initial velocity #v_(0x) = 0# (at rest)
mass #m = 1.5# #"kg"#
time #t = 0.5# #"s"#
final velocity #v_x = (5color(white)(l)"m")/(2color(white)(l)"s") = 2.5# #"m/s"#

Let's use the kinematics equation

#v_x = v_(0x) + a_xt#

to find the acceleration. Plugging in known values, we have

#2.5color(white)(l)"m/s" = 0 + a_x(0.5color(white)(l)"s")#

#a_x = 5# #"m/s"^2#

The net force #sumF# on the object is thus

#sum F_x = ma_x = (1.5color(white)(l)"kg")(5color(white)(l)"m/s"^2) = color(red)(7.5# #color(red)("N"#