A worker drops a wrench from the roof of a tall building 100m above the street and at the same instant shouts a warning to the people below. If sounds travels 340 m/s, how long after the warning is heard below does the wrench strike?

sound time ... 100 m / 340 m/s

wrench time ... 100 = 1/2 g t^2 = 4.9 t^2

To find out how long it takes for the wrench to strike after the warning is heard below, we first need to determine how long it takes for the sound to reach the ground.

The sound wave travels at a constant speed of 340 m/s. The distance between the worker and the ground is 100m.

Using the formula:

time = distance / speed

We can calculate the time it takes for sound to travel from the worker to the ground:

time = 100m / 340 m/s = 0.294 seconds

Therefore, it takes approximately 0.294 seconds for the sound of the warning to reach the people below.

Now, we know that the wrench is dropped from the roof of the building at the same instant the warning is shouted. Since the time it takes for sound to reach the ground is 0.294 seconds, the wrench will take the same amount of time to fall.

So, the wrench will strike the ground approximately 0.294 seconds after the warning is heard below.