Answer:
The greater wax moth developed the ability to hear frequencies up to 300kHz to trick bats, their chief predators.
Explanation:
Dogs commonly listen to frequencies of about 30 kHz. But nothing matches the moths 300-kHz maximum. Since there aren't any noises in an environment that get close, scientists hypothesize that greater wax moths developed super sensitive hearings to trick bats, their chief predators. it can hear wavelengths up to 300 kHz, well exceeding the range of any other creature and higher than any bat can sound.
Answer:
The height of the hill is 0.46 m.
Explanation:
Given;
mass of the child and sled, m = 50 kg
initial velocity of the sled, u = 0
final velocity of the sled, v = 3 m/s
The height of the high is calculated from the law of conservation of energy;
P.E at top = K.E at bottom
mgh = ¹/₂mv²
gh = ¹/₂v²
![h = \frac{v^2}{2g} \\\\h = \frac{3^2}{2\times 9.8} \\\\h = 0.46 \ m](https://tex.z-dn.net/?f=h%20%3D%20%5Cfrac%7Bv%5E2%7D%7B2g%7D%20%5C%5C%5C%5Ch%20%3D%20%5Cfrac%7B3%5E2%7D%7B2%5Ctimes%209.8%7D%20%5C%5C%5C%5Ch%20%3D%200.46%20%5C%20m)
Therefore, the height of the hill is 0.46 m.
1st - ‘B’
2nd - ‘A’ ( given by question 1’s answer)
3rd -because of variations in frequency ‘C’
First, we must find the vertical distance traveled upwards by the ball due to the throw. For this, we will use the formula:
2as = v² - u²
Because the final velocity v is 0 in such cases
s = -u²/2a; because both u and a are downwards, the negative sign cancels
s = 14.5² / 2*9.81
s = 10.72 meters
Next, to find the time taken to reach the ground, we need the height above the ground. This is:
45 + 10.72 = 55.72 m
We will use the formula
s = ut + 0.5at²
to find the time taken with the initial velocity u = 0.
55.72 = 0.5 * 9.81 * t²
t = 3.37 seconds