71. answer is zero (0).
72. answer is negative six (6)
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Answer:
1.) a
2.) ?
Step-by-step explanation:
Answer:
It would take approximately 6.50 second for the cannonball to strike the ground.
Step-by-step explanation:
Consider the provided function.

We need to find the time takes for the cannonball to strike the ground.
Substitute h(t) = 0 in above function.

Multiply both sides by 10.

For a quadratic equation of the form
the solutions are: 
Substitute a = -49, b = 305 and c=88

Ignore the negative value of t as time can't be a negative number.
Thus,

Hence, it would take approximately 6.50 second for the cannonball to strike the ground.
Answer:
It's b, 45 degrees
Step-by-step explanation:
1) 180-90 = 90
20 90 divided by 2 = 45