Max Height: Solving Displacement Problems

[cyspope]

Homework Statement

A rocket starts from rest and accelerates for 3.50 s with an acceleration of 5.00 m/s². If it continues to rise until its velocity is zero, what will be its maximum height?

Homework Equations

I thought I had to use the "UNIFORM MOTION with CONSTANT ACCELERATION" formula, which is d=vi*t+(1/2)*a*t²
d = distance
vi = initial velocity
t = time
a = acceleration

The Attempt at a Solution

d = 0*3.5+(1/2)(5.00 m/s²)(3.5)²

I am not sure whether I set up the problem correctly or not.

 

[drizzle]

hey cyspope,
what's the velocity of the rocket after 3.50 s? use this velocity* to determine the extra displacement, [this will be the initial velocity v_o], you may use the velocity & displacement equation.



* note the rocket will be decelerating under the effect of g = 9.8 m/s² till the velocity reaches zero.

 

[cyspope]

hey cyspope,
what's the velocity of the rocket after 3.50 s? use this velocity* to determine the extra displacement, [this will be the initial velocity v_o], you may use the velocity & displacement equation.



* note the rocket will be decelerating under the effect of g = 9.8 m/s² till the velocity reaches zero.

It doesn't says about the velocity of the rocket after 3.50 s. and How would you apply the gravity, which is 9.8 m/s² into the equation?

 

[drizzle]

hint:

A rocket starts from rest and accelerates for 3.50 s with an acceleration of 5.00 m/s²...

 

[drizzle]

don't forget, there're two different displacements, d₁ [which you can calculate using the first part of the question], and d₂ [as described above]. the maximum displacement [height] is then d₁+d₂

 

[itsameSMB]

Is the answer 63.125 m?