# Finding the maximum height pf projectile?

i need help with my hw teh problem only gives me intial velocity i dont know how to solve it with only that because its not in meters/second its in feet/second

The height of a projectile shot vertically upward from the ground with an initial velocity of 140 feet per second. Using the formula h(t)=-16t^2+140, where h=height and t=time find out the maximum height attained by the projectile

### 4 Answers

- sahsjingLv 78 years agoFavorite Answer
The formula should be h(t)=-16t^2+140t

At the maximum height, t = -140/(2*-16) = 35/8

So, the maximum height = h(35/8) = 306.25 ft

- 8 years ago
Whenever you wanna find the maximum height of something goin up and down, your final velocity (V) is always gonna be zero. So you can use the formula acceleration = (final velocity - initial velocity) / time. You'll find T and plug that into the h(t) formula

Acceleration due to gravity is 35.3 feet/sec^2 btw

- chizmarLv 43 years ago
i'm uncertain if this subject is solvable. Are you meant to furnish a cost for the respond or an expression? If the inital vertical velocity exchange into given, or preliminary velocity and perspective have been given so as which you will discover the preliminary vertical velocity, then it would be a threat to discover the max top using the equation. v^2-u^2=2ad and time taken using a=(v-u)/t additionally, if the gap the place it lands exchange into given, you may desire to discover the time taken to return and forth (v=d/t as horizontal velocity maintains to be consistent), and then discover the different documents, and discover the max top/time.