The echo is heard 2.80 s later, this means this is the time the sound takes to travel to the reflecting object and then back to us. So, during this time, the sound wave has covered the distance L between us and the object twice:
The speed of the sound wave is:
, and since it is moving by uniform motion, we can find the distance covered by the wave using
And we said this corresponds to twice the distance between us and the reflecting object, so:
so, the object is 480 meters away.
Answer:
7.19 * 10^14J
Explanation:
Given that
Density of water Pwater= 1000kg/m3
R=2.1km = 2.1*10^3m
H= 2.3cm. = 2.3*10^-2m
Lv water= 2256 * 10^3J/kg
First, mass of water need to be calculated, using an imaginary cylinder
Density= Mass /Volume
Mass= Density* Volume
Volume of a cylinder= πR2h
Therefore mass= PπR2H
= 1000 * π * (2.1 *10^3)^2 * (2.3 * 10^-2)
= 3.18 *10^8
Heat Released Qv = mLV
= 3.18*10^8 * 2236*10^3
= 7.19 * 10^14J
Answer: D
Explanation:
When an object falls gravity is pulling down on it and is picking up speed, but as it gains speed air resistance becomes a faster. Air resistance increases with speed. And that force keeps it from accelerating eventually the object will pick up speed such that the force due to air resistance will keep it from getting any more speed at that point force due to air resistance is equal to its weight (mg) and the net force is equal to zero so it won’t accelerate any more at that point it is said to be moving in terminal velocity.
When an object has reached terminal velocity, it will have a constant velocity
Honest, the map is so tiny, and so fuzzy when I blow it up, I really can't see anything on it clearly. But I think maybe I do see a letter ' C ' in the eastern Mediterranean, with a curved line over to the southern Gaza strip, where it meets Sinai. So I'll say it's the Gaza Strip.
Answer:
Crumple zones are designed to absorb and redistribute the force of a collision. ... Also known as a crush zone, crumple zones are areas of a vehicle that are designed to deform and crumple in a collision. This absorbs some of the energy of the impact, preventing it from being transmitted to the occupants.
