The answer for number 4: Temperature is an average of average heat. Heat is the average kinetic energy and thermal energy is kinetic energy.
(I can't see the answer for number 10... it would be good if you told me the question)
Since the ratio is 3:4, and 12/4 is 3 than you do 3x3 and get 9 so the answer is 9:12 or 9 boys and 12 girls. To check your answer, you can do 3/4 (for 3:4) and that is 0.75. If you do that with 9:12 you also get 0.75.
Answer:
The ball will be 84 feet above the ground 1.125 seconds and 4.5 seconds after launch.
Step-by-step explanation:
Statement is incorrect. Correct form is presented below:
<em>The height </em>
<em> of an ball that is thrown straight upward from an initial position 3 feet off the ground with initial velocity of 90 feet per second is given by equation </em>
<em>, where </em>
<em> is time in seconds. After how many seconds will the ball be 84 feet above the ground. </em>
We equalize the kinematic formula to 84 feet and solve the resulting second-order polynomial by Quadratic Formula to determine the instants associated with such height:

(1)
By Quadratic Formula:

,
The ball will be 84 feet above the ground 1.125 seconds and 4.5 seconds after launch.
Answer: Stephanie read more than 7 books because 8 points for 9 books each is equal to 72 points, which is the total amount of books she read.
Step-by-step explanation:
72 ÷ 8 × 9
x = 9
Hope this helped! :D