Final answer:
The speed of the rocket 10 seconds after liftoff is 60 ft/s.
Step-by-step explanation:
To find the speed of the rocket 10 seconds after liftoff, we can differentiate the equation for the height of the rocket with respect to time. In this case, the equation for the height of the rocket is given as h = 3t^2. Taking the derivative of this equation with respect to time will give us the rate of change of height with respect to time, which is the speed of the rocket. The derivative of 3t^2 with respect to t is 6t. Plugging in t = 10 into the derivative, we get 6(10) = 60.