# Dynamics And Kinematics Problem

## Homework Statement

Given: m = 17kg Vi = 0 Fa=42N θ=25 Mu=0.15 T=125s

Diagram: http://s14.postimage.org/euy3whikh/New_Bitmap_Image.png [Broken]

Find: Δd

a block accellerates from rest for 125s find the displacement. Frictional forces act on the block.
A force applied is 25 degrees above the horizontal. Find the displacement

Fnet=Ma
Δ=vit+a/2(t)^2

## The Attempt at a Solution

Fnety=Fn + FaSin25 -Fg = 0

Fn= Fg - FaSin25

Fnetx=mAx=FaCos25 - Ffr

Ffr=Mu*Fn

Ffr= Mu*(Fg - FaSin25)

mAx = Facos25 - Mu*(Fg-FaSin25)

Ax= (Facos25 - Mu*(Fg-Fasin25))/m

Ax= 0.93 m/s^2 [--->]

Δd = vit + Ax/2(t)^2

Δd = + Ax/2(t)^2

I'm not sure if this is correct or not, but my friend took a note in which it was the same question and he wrote down 78m.. I've done this question by myself to check everything but it bothers me the answer was wrong on the note he took, can some one infrom me if this is the correct way and if i have the correct answer to this problem please?

Did i not take something into account maybe..?

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haruspex