A projectile is shot upwards with an initial velocity of 30m/s. Its height at time t is given by h=30t-4.9t^2. During what period of time is the projectile more than 40m above the ground? Express your answer rounded to the nearest hundredths.
A projectile is shot upwards with an initial velocity of 30m/s. Its height at time t is given by h=30t-4.9t^2. During what period of time is the projectile more than 40m above the ground? Express your answer rounded to the nearest hundredths.