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You push an object, initially at rest, across a frictionless floor with a constant force for a time interval Dt, resulting in a final speed of v for the object. You then repeat the experiment, but with a force that is twice as large. What time interval is now required to reach the same final speed v? Defend your answer.

(a) 4 Dt

(b) 2 Dt

(c) Dt

(d) Dt/2

(e) Dt/4