Answer:

Explanation:
The speed is by definition the distance traveled divided over the time it takes to travel that distance. In this case, this distance is the circumference of the wheel, so we have:

where we have written the circumference in terms of its radius.
For our values we then obtain the value:

Answer:

Explanation:
When teacher falls into the cliff then she shout for Help at the same time
so here we know that sound will go down and reflect back up
so here in 3 s distance traveled by the sound



now in the same time the distance that teacher will fall down is given as



now total distance traveled by teacher and sound in 3 s


this total distance must be equal to twice the height of the cliff


0.616 is the distance from the top
of the building to the top of the window.
The answer is ultra violet radiation. From the air