Answer:
2.62seconds
Explanation:
Echo occurs when sound reflects and causing a delay before getting to the listener.
Let x be the distance from between the source and the reflector
t be the time taken for the echo to occur
v be the velocity of sound in air.
Using the relationship 2x = vt
t = 2x/v
Given x = 450metres
v = 343m/s
t = 2(450)/343
t = 900/343
t = 2.62seconds
It will take 2.62 seconds for him to hear his own voice echo off of the wall.
Answer:
275 kPa
Explanation:
mass of the gas=m=1.5 kg
initial volume if the gas=V₁=0.04 m³
initial pressure of the gas= P₁=550 kPa
as the condition is given final volume is double the initial volume
V₂=final volume
V₂=2 V₁
As the temperature is constant
T₁=T₂=T
=
putting the values in the equation.
=
P₂=
P₂=
P₂=275 kPa
So the final pressure of the gas is 275 kPa.
1) Let's call
the speed of the southbound boat, and
the speed of the eastbound boat, which is 3 mph faster than the southbound boat. We can write the law of motion for the two boats:
2) After a time
, the two boats are
apart. Using the laws of motion written at step 1, we can write the distance the two boats covered:
The two boats travelled in perpendicular directions. Therefore, we can imagine the distance between them (45 mi) being the hypotenuse of a triangle, of which
and
are the two sides. Therefore, we can use Pythagorean theorem and write:
Solving this, we find two solutions. Discarding the negative solution, we have
, which is the speed of the southbound boat.
B. galaxies
Explanation:
Spiral, elliptical, irregular and barred spiral are descriptions of different shapes of galaxies.
A galaxy is a constellation or group of stars.
- A spiral galaxies are the most common and they have spiral arm shapes.
- A barred spiral is made up of spiral shape and bar in the middle.
- Elliptical galaxies are spherical in shape.
- Irregular galaxies are usually not patterned and lacks form.
learn more:
Galaxy recession velocity brainly.com/question/12617031
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Answer:
C
Explanation:
From the question we are told that a vector on the x and y plane face their negative axis
Generally in the x and y plane thr negative y axis is made to face down opposite the positive y axis
Whilst the negative x axis faces the left which is also alternate to the positive x axis
Generally A vector pointing towards the x and y negative axis fro the origin (0) will definitely be in the third quadrant