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Homework Help: Lawn mower problem

  1. Nov 16, 2004 #1
    A person pushes a 14.5 kg lawn mower at a constant speed with a force of 88.0 N directed along the handle, which is at an angle of 45.0 degrees to the horizontal. (a) Draw the free-body diagram showing all forces acting on the mower. Calculate (b) the horizontal retarding force on the mower, then (c) the nomal force exerted vertically upward on the mower by the ground, and (d) the force the person must exert on the lawn mower to accelerate it from rest to 1.5 m/s in 2.5 seconds (assuming the same retarding force).

    I got the free body diagram but I'm lost on the rest of it.
  2. jcsd
  3. Nov 16, 2004 #2
    For (b), the "retarding" force (that's an odd way of wording I've never seend) is basically that which opposes the motion of the lawn mower. Do you know which force that is, and then how to calculate it?
    For (c), you know that the normal force and the gravitational force are equal and opposite forces. Use that fact to find the normal force.
    For (d), find the acceleration of the object and then input into the ubiquitous equation [tex]F=ma[/tex].

    Hope that helps! ;)
    Last edited: Nov 16, 2004
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