Answer:
10 ft/s and 6.818 mi/hr
Step-by-step explanation:
We can represent the situation with the following diagram:
When the angle is 63 degrees, the value of h can be calculated using a trigonometric function as:

Because h is the opposite side and 100 ft is the adjacent side. Solving for h, we get:

In the same way, when the angle is 67.9 degrees, we can calculate the height as follows:

Now, we can calculate the speed in ft per second as follows:

Finally, 1 mile = 5280 ft and 1 hour = 3600 seconds, so we can convert to miles per hour as:

Therefore, the answers are:
10 ft/s and 6.818 mi/hr