The frequency of the wave is 6800 Hz
<u>Explanation:</u>
Given:
Wave number, n = 20
Speed of light, v = 340 m/s
Frequency, f = ?
we know:
wave number = 

Therefore, the frequency of the wave is 6800 Hz
Answer:
b. add a magnetic metal core
Explanation:
a p e x test
The initial horizontal velocity of the rock, in m/s is 21.241 m/s.
<h3>What is projectile?</h3>
When an object is thrown at an angle from the horizontal direction, the object is said to be in projectile motion. The object which follows the projectile motion.
Time taken by the stone to reach the ground is
t = √2h/g
t = √(2x 86)/9.81
t = 4.19s
The horizontal velocity is
V(x) = Horizontal distance traveled / Time taken t
Put the values, we get
V(x) = 89 m/4.19 s
V(x) = 21.241 m/s
Thus, the horizontal velocity is 21.241 m/s
Learn more about projectile.
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Answer:
a) N = 343 [N]
Explanation:
We must remember Newton's third law, which tells us that the force acting on a body is equal to the normal reaction force of equal magnitude but acting in the opposite direction.

where:
m = mass = 35 [kg]
g = gravity acceleration = 9.81 [m/s²]
![N = 35*9.8\\N= 343 [N]](https://tex.z-dn.net/?f=N%20%3D%2035%2A9.8%5C%5CN%3D%20343%20%5BN%5D)