The object will reach a height of 90ft
To solve this exercise we are going to use the discriminant of the quadratic polynomial ax²+bx+c=0, which is b²-4ac.
If the discriminant is negative, then there are no real solutions to the equation.
If the discriminant is zero, there is only one solution.
If the discriminant is positive, there are two real solutions.
We have the equation h(t)=18t-16t² which describes the model of the height h (feet) reached in t (seconds) by an object propelled straight up from the ground at a speed of 80 ft/s. We want to use the discriminant to find whether the object will ever reach a height of 90ft.
First, we have to rewrite the equation to the form ax²+bx+c=0 and we know the height that is possible to reach for the object h=90ft.
90 = 80t-16t² ----------> -16t²+80t-90=0
Using the discriminan equation D = b²- 4ac.
From the quadratic polynomial -16t²+80t-90=0, we have a = -16, b = 80, and c = -90
D = (80)² - 4 (-16)(-90)
D = 6400 - 5760 = 640
Since the discriminant D is positive, the object will reach a height of 90ft.
The energy from the sun reaches Earth mostly by radiation. The correct answer to the question is option C
To determine the correct answer to the question, let us remind ourselves about how heat energy is been transferred. This is shown below:
Heat is a form of energy and can be transferred by:
From the above information, we can see that electromagnetic transmission (which includes light) requires no medium.
Thus, we can say that the energy from the sun reaches the earth by radiation. The correct answer to the question is option
Learn more about radiation:
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Kepler
Newton
Ptolemy
Answer: Kepler
Explanation:
At the time when general masses believed in the geocentric model of universe where Earth is the center of the universe. Tycho Brahe was a Danish noble man. Kepler was the student of Tycho Brahe. Kepler firmly believed that Sun was the center of the universe. The extensive data records collected by Brahe eventually helped his student Kepler to formulate laws that defined orbits of the planet. Their work contributed to confirm heliocentric model.
Answer:
i dont understand sorry
Answer:
Explanation:
4 meters east
b.Water is important for shipping and trade.
c.Water is a valuable, profitable commodity.
d.All of the above
Answer;
-All of the above
Explanation;
-Water is one of the most important substances on earth. All plants and animals must have water to survive. If there was no water there would be no life on earth. Apart from drinking it to survive, people have many other uses for water such as cooking, washing clothes, cleaning, recreation, etc.
-Water is also essential for the healthy growth of farm crops and farm stock and is used in the manufacture of many products. Water is also important in our bodies; It facilitates digestion of food and absorption of nutrients through their dissolving in water, transports nutrients, chemicals and heat throughout the body. Water is our primary source of food.