Two stones are thrown from the top edge of a building with a speed of 20 m/s, one straight down and the other straight up. The first one hits the street in a time t1. How much later is it before the second stone hits

Respuesta :

Answer:

Second stone hist at 4.08 s later.

Explanation:

The second stone straight up, so we need to find the rise and descent time.

[tex]v_{f}=v_{i}-gt[/tex]

At the top, the final speed is 0 and t is the rise time.

[tex]0=20-gt_{r}[/tex]

[tex]t_{r}=\frac{20}{9.81}[/tex]

[tex]t_{r}=2.04 s[/tex]

Let's recall that the rise time is equal to the descent time.

So the total time of the stone will be

[tex]t_{t}=4.08 s[/tex]

Now, the second stone hits the street in t2 = 4.08 s + t1 s

But we just need the time after the first stone hist the street. So we just subtract the time t1 to the second time t2, which means t2 = 4.08 s.

Therefore stone hist at 4.08 s later.

The second stone hits the wall 4.08 seconds later.

To solve this question, we will use the equation of motion. In particular, the first equation of motion which states that;

v = u + at, where

v = the final velocity

u = the initial velocity

a = acceleration of gravity

t = time taken by the stone.

From the question, we're told that the stone is thrown with a speed of 20 m/s, which is the initial velocity. And a final velocity, v of 0 m/s. Using a constant of 9.81 for acceleration of the stone. We have,

0 = 20 - 9.81 × t

20 = 9.81t

t = [tex]\frac{20}{9.81}[/tex]

t = 2.039or 2.04 seconds.

Assuming that the time taken to ascent = time taken to descent, this means that the total time taken will be 2.039 + 3.039 = 4.078 seconds or 4,08 seconds.

visit https://brainly.com/question/24040430 to learn more about the first equation

Otras preguntas