The figure below gives, as a function of time t, the force component Fx that acts on a 3.00 kg block that can move only along the x-axis. At t=0, the block is moving in the positive direction of the axis with a speed of 3.0 m/s. what are its (a) speed and (b) direction of travel at t = 11s?

Question

The figure below gives, as a function of time t, the force component Fx that acts on a 3.00 kg block that can move only along the x-axis.  At t=0, the block is moving in the positive direction of the axis with a speed of 3.0 m/s.  what are its (a) speed and (b) direction of travel at t = 11s?

anonymous · Answer

Here is the picture (tried to draw it) |dw:1351013847724:dw|So I started off using Fx=ma (a in the x-direction). Solve for acceleration to get a=Fx/m.
When I plugged in the values it was -4/3 m/s^2.  I put this into v=v0+at and got v=-35/3 m/s.  The answer is eight.  Can anybody spot my mistake?