# Physics 11 - Dynamics

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While standing on a horizontal frictionless surface a 50.0 kg student pushes against a wall with an average force of 125 N to the right for 0.110 s. Calculate the velocity of this student at 1.110 s.

My answer: Vf = 0.275 m/s

My solutions book has Vf = -0.275 m/s OR 0.275 m/s to the left.

My question is where does the negative or the "to the left" come from? My understanding is that "right" is positive.

Thanks.

• Physics 11 - Dynamics -

250 kg•m/s

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