Answer:
1640
Step-by-step explanation:
Even, positive integers
2+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48+50+52+54+56+58+60+62+64+66+68+70+72+74+76+78+80 = 1640
The maximum height of the projectile is the maximum point that can be gotten from the projectile equation
The projectile reaches the maximum height after 5 seconds
The function is given as:

Differentiate the function with respect to t

Set to 0

So, we have:

Collect like terms


Solve for t


Hence, the projectile reaches the maximum after 5 seconds
Read more about maximum values at:
brainly.com/question/6636648
8 I guess? The question isn’t very well written
Answer:ayayaa
Step-by-step explanation: