When the ball hits the ground, the height is 0.
0 = 100 - 16t²
0 = (10 - 4t)(10 + 4t)
0 = 10 - 4t or 0 = 10 + 4t
4t = 10 or -4t = 10
t = 
or t = 
Time cannot be negative (unless you have a time machine) so disregard
Answer: t = 
= 2.5 seconds
Answer:
Discount
Step-by-step explanation:
A <u>discount</u> is a deduction from the original price of an item.
If a question has four possible answers, and you are strictly guessing regarding which of them is correct, then the chances of your choosing the correct one from the four is 1 in 4, or 0.25.
Answer:
Infinitely many solutions.
Step-by-step explanation:
Let's begin by carrying out the indicated multiplications, which must be done before any addition or subtraction:
2(8r+5)-3=4(4r-1)+11 becomes 16r + 10 - 3 = 16r - 4 + 11.
Subtracting 16r from both sides, we get 10 - 3 = - 4 + 11, or 7 = 7
This is always true, so we can conclude that this equation has infinitely many solutions.
The average rate, in miles per hour, of the rail portion of the trip is; D: 75
<h3>How to calculate the average speed?</h3>
Since exactly 1/3 of the distance travelled was by rail, then we can say that;
(1/3) * (90) = 30 miles
We are told that part of the trip took 1/5 of the travel time. Thus;
Time it takes to travel that distance is:
(1/5) * (2) = 2/5 of an hour
Average rate is;
30/(2/5) = 150/2 = 75 mph
Read more about Average speed at; brainly.com/question/4931057
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