Im not sure where to start with this one...
1 answer:
You might be interested in
Answer:
C
Step-by-step explanation:
There’s nothing hard with this
You need to know special right triangles
This is a 30,60, 90 triangle
We automatically know becuase theres. Right angle (90) and a 60 degree angle
now the formula is the smallest side is (n) {I’m using N becuase theres already an X) or in this case, 6
The hypotenuse, the one directly above the 2nd biggest side, or the diagnoal side is 2n or (12). Now we know what X is in this situation which is 12. So that narrows it to 2 answers
Now the side on the bottom of the hypotenuse, the second biggest side is used in the formula N. So we know what N is in the beginning, 6 so we just plug that in and well get C. Attached is a photo on q 30, 60, 90 special right triangle
Ok, so the question is based on geometric progression. Remember, the formula for calculating the nth-term of a geometric progression is: . The a in the expression stands for the 1st term of the sequence, and r is the common ratio of the elements of the sequence. Now let's take a look at the problem.
"A ping pong ball has a 75% rebound ration". We can infer that our common ratio, r, is 75% which is 0.75.
"When you drop it from a height of k feet...", this means the first height you drop it from, a.k.a, the first term.
Now going back to the expression, the nth-term = , we can substitute our common ration, 0.75 with r, and our 1st term, k, with a. This becomes:
. This becomes our expression.
a. The highest height achieved by the ball after six bounces. Our nth-term here is 6, so let's use our expression to find the 6th term.
b. The total distance travelled by the ball when it strikes the ground for the 12th time. This involves the use of the sum of elements in the geometric progression. The formula for that is , provided that r is less than 1, which it is in this case, since 0.75 is less than one. Our nth-term here is 12, so we substitute.