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?

1 Answer
Jul 4, 2017

sumF_x = 7.5 "N"

Explanation:

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"