Kathy buys a sports car that can accelerate at the rate of 4.9 m/s/s. She decides to test the car by racing with her friend Stan. Both start from rest, but Stan leaves the starting line 1.0 second before Kathy. Stan moves with a constant acceleration of 3.5 m/s/s while Kathy maintains her acceleration at 4.9 m/s/s. At what time does Kathy overtake Stan?