Question

Помогите физика 10 класс!!!! тіло, що вільно падає, останні 200 метрів шляху пролетіло за 4 с. скільки часу падало тіло і з якої висоти? яка кінцева швидкість тіла при падінні?

Answer 1

Высота падения h=gt²/2  h₁=g(t-4)² /2
h-h₁=200м    g=10 м/с²
gt²/2 - g(t-4)²/2 = 200
10t² - 10(t²-8t+16) = 400 
80t-160 = 400
80t=560
t=7c (падения)
h=10*49/2 = 245м
V=gt = 10*7=70 м/с      

Answer 2

Problem Analysis

We are given that an object freely falls and covers the last 200 meters of its path in 4 seconds. We need to determine the time it took for the object to fall and the height from which it fell, as well as the final velocity of the object during the fall.

Solution

To solve this problem, we can use the equations of motion for free fall. The key equation we will use is:

s = ut + (1/2)gt^2

where: - s is the distance traveled (200 meters in this case) - u is the initial velocity (which is 0 for an object in free fall) - g is the acceleration due to gravity (approximately 9.8 m/s^2) - t is the time taken (4 seconds in this case)

Calculating the Time and Height

Let's substitute the given values into the equation and solve for t:

200 = 0 + (1/2)(9.8)t^2

Simplifying the equation, we get:

200 = 4.9t^2

Dividing both sides by 4.9, we get:

t^2 = 40.816

Taking the square root of both sides, we find:

t ≈ 6.39 seconds

So, the object took approximately 6.39 seconds to fall.

Now, let's calculate the height from which the object fell. We can use the equation:

s = ut + (1/2)gt^2

Substituting the known values, we have:

h = 0 + (1/2)(9.8)(6.39)^2

Simplifying the equation, we get:

h ≈ 196.08 meters

Therefore, the object fell from a height of approximately 196.08 meters.

Calculating the Final Velocity

To calculate the final velocity of the object during the fall, we can use the equation:

v = u + gt

Since the initial velocity (u) is 0 for an object in free fall, the equation simplifies to:

v = gt

Substituting the known values, we have:

v = 9.8 * 6.39

Simplifying the equation, we find:

v ≈ 62.82 m/s

Therefore, the final velocity of the object during the fall is approximately 62.82 m/s.

Summary

In summary, the object took approximately 6.39 seconds to fall, starting from a height of approximately 196.08 meters. The final velocity of the object during the fall was approximately 62.82 m/s.