Can someone please help with these 4 questions?

Answer:
Q4. 2144 Q5. -16 Q6. Downwards Q7. 0 seconds
Step-by-step explanation:
Q4. h(t) = -16t² + 2400 Substitute 4 for t
h(4) = -16(4)² + 2400 Simplify the exponent
h(4) = -16(16) + 2400 Multiply
h(4) = -256 + 2400 Add
h(4) = 2144
Q5. I graphed the equation on the graph below to find the instantaneous velocity. The instantaneous velocity is -16.
Q6. At 4.5 seconds, the water rocket is traveling down because the highest point the rocket goes is at 2.8, so 4.5 is traveling downwards.
Q7. 0 seconds because the rocket goes 0 feet in 0 seconds.
If these answers are correct, please make me Brainliest!