By conducting exhaustive, high-intensity online research for about 15 seconds, I found a source that says the speed of sound in copper is 4600 m/s. (You could easily have completed the same research project in about 1/3 of the time it took you to type and post the question here.)
Time it takes = (distance) / (speed)
Time = (25,000 meters) / (4600 m/s)
Time = (25 / 4.6) km-sec/km
<em>Time = 5.43 seconds </em>
Answer:
Answer D : about 1067 meters
Explanation:
There are two steps to this problem:
1) First find the time it takes the plane to stop using the equation for the acceleration:

Where Vf is the final velocity of the plane (in our case: zero )
Vi is the initial velocity of the plane (in our case: 80 m/s)
is the acceleration (in our case -3 m/s^2 - notice negative value because the velocity is decreasing)

with units corresponding to seconds given the quantities involved in the calculation.
2) Second knowing the time it took the plane to stop, now use that time in the equation for the distance traveled under accelerated motion:

Where the answer results in units of meters given the quantities used in the calculation.
We round this to 1067 meters
Answer:
Explanation:
Atmospheric pressure = 7 x 10⁴ Pa
force on a disk-shaped region 2.00 m in radius at the surface of the ocean due to atmosphere = pressure x area
= 7 x 10⁴ x 3.14 x 2 x 2
= 87.92 x 10⁴ N
b )
weight, on this exoplanet, of a 10.0 m deep cylindrical column of methane with radius 2.00 m
Pressure x area
height x density x acceleration of gravity x π r²
= 10 x 415 x 6.2 x 3.14 x 2 x 2
=323168.8 N
c ) Pressure at a depth of 10 m
atmospheric pressure + pressure due to liquid column
= 7 x 10⁴ + 10 x 415 x 6.2 ( hρg)
= 7 x 10⁴ + 10 x 415 x 6.2
(7 + 2.57 )x 10⁴ Pa
9.57 x 10⁴ Pa
a)
Y₀ = initial position of the stone at the time of launch = 0 m
Y = final position of stone = 20.0 meters
a = acceleration = - 9.8 m/s²
v₀ = initial speed of stone at the time of launch = 30.0 m/s
v = final speed = ?
Using the equation
v² = v₀² + 2 a (Y - Y₀)
inserting the values
v² = 30² + 2 (- 9.8) (20 - 0)
v = 22.5 m/s
b)
Y₀ = initial position of the stone at the time of launch = 0 m
Y = maximum height gained
a = acceleration = - 9.8 m/s²
v₀ = initial speed of stone at the time of launch = 30.0 m/s
v = final speed = 0 m/s
Using the equation
v² = v₀² + 2 a (Y - Y₀)
inserting the values
0² = 30² + 2 (- 9.8) (Y - 0)
Y = 46 m