Question

H=300м,Va=5м/с,найти время ​

Answer 1

Ответ:

t=h/Va

t(время)=300/5=60с

Answer 2

To find the time it takes for an object to reach a height of 300m with an initial vertical velocity of 5m/s, we can use the equations of motion for vertical motion.

The equation that relates the displacement, initial velocity, time, and acceleration for vertical motion is:

H = Va*t + (1/2)at^2

Where: H is the displacement (300m in this case), Va is the initial vertical velocity (5m/s), t is the time, and a is the acceleration due to gravity (-9.8m/s^2).

Rearranging the equation, we get:

0 = (1/2)*(-9.8)t^2 + 5t - 300

This equation is a quadratic equation in terms of t. We can solve it using the quadratic formula:

t = (-b ± √(b^2 - 4ac)) / (2a)

For our equation, the coefficients are: a = (1/2)*(-9.8) = -4.9 b = 5 c = -300

Plugging these values into the quadratic formula, we have:

t = (-5 ± √(5^2 - 4*(-4.9)(-300))) / (2(-4.9))

Simplifying further:

t = (-5 ± √(25 - 5880)) / (-9.8) t = (-5 ± √(-5855)) / (-9.8)

Since the value inside the square root is negative, the equation does not have real solutions. This means that the object will not reach a height of 300m with an initial velocity of 5m/s.