(1 point)
7. a marble is rolled down a ramp. the distance it travels is described by the formula d = 490t^2 where d is the distance in centimeters that the marble rolls in t seconds. if the marble is released at the top of a ramp that is 3,920 cm long, for what time period will the marble be more than halfway down the ramp?

t> 2
t> 4
t>8
t> 16