This question can be solved by using the equations of motion.
a) The initial speed of the arrow is was "9.81 m/s".
b) It took the arrow "1.13 s" to reach a height of 17.5 m.
a)
We will use the second equation of motion to find out the initial speed of the arrow.

where,
vi = initial speed = ?
h = height = 35 m
t = time interval = 2 s
g = acceleration due to gravity = 9.81 m/s²
Therefore,

<u>vi = 9.81 m/s</u>
b)
To find the time taken by the arrow to reach 17.5 m, we will use the second equation of motion again.

where,
g = acceleration due to gravity = 9.81 m/s²
h = height = 17.5 m
vi = initial speed = 9.81 m/s
t = time = ?
Therefore,

solving this quadratic equation using the quadratic formula, we get:
t = -3.13 s (OR) t = 1.13 s
Since time can not have a negative value.
Therefore,
<u>t = 1.13 s</u>
Learn more about equations of motion here:
brainly.com/question/20594939?referrer=searchResults
The attached picture shows the equations of motion in the horizontal and vertical directions.
Answer:

Explanation:
From this exercise, our knowable variables are <u>hight and initial velocity </u>


To find how much time does the <u>ball strike the ground</u>, we need to know that the final position of the ball is y=0ft


Solving for t using quadratic formula


or 
<u><em>Since time can't be negative the answer is t=6.96s</em></u>
Specific heat<span> is another physical property of matter. ... we con now ask the following question: by </span>how much<span> will the </span>temperature<span> of an .</span>
Answer:
Please find the complete solution in the attached file.
Explanation: