Hello
Let's convert first the height from foot to meters:

This is the space covered by the ball in its accelerated motion, where the acceleration is the gravitational acceleration:

The law of motion is given by

Re-arranging, we can get the total time of the motion:

which is the time the ball takes to hit the ground.
4 because its not yet moving. It has kinetic energy, it just hasn’t been used yet.
C2 = a2 + b2
29^2 = a^2 + 20^2
841 = a^2 + 400
441 = a^2
a = 21
Shield volcanos have the most predictable eruptions.
P = density × gravity acceleration × height
P = 1200 × 9.81 × 15/100
P = 1765.8