If a toy rocket is launched vertically upward from ground level with an initial velocity of 135 feet per second, then its height h after t seconds is given by the equation h(t) = -16t^2 + 135t. How long will it take the rocket to return to the ground? A. 8.4 seconds

B. 16 seconds

C. 4.2 seconds

D. 135 seconds

i dont know men

step-by-step explanation:

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)

answer: the answer is one

step-by-step explanation:

pemdas, in this situation there is no parenthesis or exponents so you go to multiplication, 1x1=1, then division 1/1= 1 then addition 1+1=2 then subtraction 2-1=1

too hard the other guy did it

step-by-step explanation: