The sound wave that travel through the are is called the <em>amplitude</em> or <em>frequency you can use either of them because there both correct.</em>
Vo = 89 m/s
angle: 40°
=> Vox = Vo * cos 40° = 89 * cos 40°
=> Voy = Vo. sin 40° = 89 * sin 40°
x-movement: uniform => x =Vox * t = 89*cos(40)*t
x = 300 m => t = 300m / [89m/s*cos(40) = 4.4 s
y-movement: uniformly accelerated => y = Voy * t - g*t^2 /2
y = 89m/s * sin(40) * (4.4s) - 9.m/s^2 * (4.4)^2 / 2 = 156.9 m = height the ball hits the wall.
I recently did this topic in science class - the answer is A ;)
is the magnitude of the magnetic field made by the current
<u>Explanation:</u>
Given data:

Magnetic field of earth, 
We need to find the magnetic field of wire, 
The compass needle moves toward a direction of magnetic field. The current in wire makes a magnetic field in available space where the compass is on the ground. The vector sum of the Earth's magnetic field and the wire's magnetic field represents the net magnetic field, as shown in the attached drawing, expressing the angle:

By substituting the given values, we get


The frequency for a fundamental pipe is given as:
f = v/4L
L is equal to the length of the pipe
Since L = Lo/2 where Lo is the original length of the pipe, the
new frequency would be:
f = (v/4)/(Lo/2)
f = 2 (v/4Lo)
Since v/4Lo = fo, therefore:
f = 2 fo