Question

Высота над землей подброшенного мяча меняется по закону h(t)=2+13t-5t^2 где h высота в метрах t время в секундах прошедшее с момента броска. Сколько секунд мяч будет находиться на высоте не менее 10м ответ разверните как можно больше!!! за ответ не засчитаю

Answer 1

-5t^2+13t+2>=10,
5t^2-13t+8<=0,
D=169-4*5*8=9,
t1=13-3/2*5=1 c,
t2=13+3/10=1,6 c,
т.к.парабола ветвями вверх, значения функции<=0, когда ее вершина под осью ох( в данном случае оt), т.е при t принадлежащем отрезку
[1;1,6] Ответ: мяч будет не ниже 10м от1 до 1,6 с полета, т.е. 0,6 с.

Answer 2

Высота должна быть больше или равно 10, значит
h ≥ 10
-5t^2 + 13t + 2 ≥ 10
-5t^2 + 13t - 8 ≥ 0
D = 169 - 160 = 9
t1 = (-13 - 3)/-10 = 1,6
t2 = (-13 + 3)/-10 = 1
Дальше тупо построить примерную параболу (ветви направлены вниз)
и взять за ответ тот промежуток, где парабола над осью абсцисс(Х),включая 1 и 1.6
Ответ: промежуток [1;1,6]

Answer 3

Calculation of the Time the Ball will be at a Height of at Least 10m

To determine the time the ball will be at a height of at least 10m, we need to find the values of 't' that satisfy the equation h(t) ≥ 10.

Given the equation h(t) = 2 + 13t - 5t^2, where h represents the height in meters and t represents the time in seconds since the ball was thrown, we can set up the inequality:

2 + 13t - 5t^2 ≥ 10

To solve this inequality, we can rearrange it to form a quadratic equation:

5t^2 - 13t + 8 ≤ 0

Now, we can solve this quadratic equation to find the values of 't' that satisfy the inequality.

Using the quadratic formula, t = (-b ± √(b^2 - 4ac)) / (2a), where a = 5, b = -13, and c = 8, we can calculate the roots of the equation.

Calculating the discriminant, D = b^2 - 4ac:

D = (-13)^2 - 4 * 5 * 8 = 169 - 160 = 9

Since the discriminant is positive, there are two real roots for the equation.

Using the quadratic formula, we can calculate the roots:

t = (-(-13) ± √(9)) / (2 * 5)

Simplifying the equation:

t = (13 ± 3) / 10

This gives us two possible values for 't':

t1 = (13 + 3) / 10 = 16 / 10 = 1.6 seconds t2 = (13 - 3) / 10 = 10 / 10 = 1 second

Therefore, the ball will be at a height of at least 10m for 1 second and 1.6 seconds after it is thrown.

Please note that the provided search snippet does not directly answer the question. However, the solution provided above is derived from the given equation and the process of solving the quadratic inequality.