Answer:
∆h = 0.071 m
Explanation:
I rename angle (θ) = angle(α)
First we are going to write two important equations to solve this problem :
Vy(t) and y(t)
We start by decomposing the speed in the direction ''y''


Vy in this problem will follow this equation =

where g is the gravity acceleration

This is equation (1)
For Y(t) :

We suppose yi = 0

This is equation (2)
We need the time in which Vy = 0 m/s so we use (1)

So in t = 0.675 s → Vy = 0. Now we calculate the y in which this happen using (2)

2.236 m is the maximum height from the shell (in which Vy=0 m/s)
Let's calculate now the height for t = 0.555 s

The height asked is
∆h = 2.236 m - 2.165 m = 0.071 m
The acceleration of the runner in the given time is 2.06m/s².
Given the data in the question;
Since the runner begins from rest,
- Initial velocity;

- Final velocity;

- Time elapsed;

Acceleration of the runner; 
<h3>Velocity and Acceleration</h3>
Velocity is the speed at which an object moves in a particular direction.
Acceleration is simply the rate of change of the velocity of a particle or object with respect to time. Now, we can see the relationship from the First Equation of Motion

Where v is final velocity, u is initial velocity, a is acceleration and t is time elapsed.
To determine the acceleration of the runner, we substitute our given values into the equation above.

Therefore, the acceleration of the runner in the given time is 2.06m/s².
Learn more about Equations of Motion: brainly.com/question/18486505
Answer:
It's either B or D, I'm not positive which it is
Explanation:
Correct option is=A
because 25mph means=25miles per hour