In an engineering test, a rocket sled is propelled into a target. If the sled's distance d in meters from the target is give...

In an engineering test, a rocket sled is propelled into a target. If the sled's distance d in meters from the target is given by the formula d = 1.5t² + 120, where t is the number of seconds afer rocket ignition, then how many seconds have passed since rocket ignition when the sled is 10 meters from the target ?