Answer:
Speed of an EM wave is different in air and in water.
Explanation:
The speed of an EM wave is different in air and water .
Since the frequency of any EM wave is its characteristic property, therefore wavelength and speed of EM wave Change on changing the medium of propogation.
Also the refractive index
of any medium is defined as the ratio between light's speed in vacuum to the light's speed in any medium.
Also ,it can be define as speed of any EM wave in any medium = c/refractive index of medium.
Here, c is the speed of light,
.
Complete Question
A 0.025-kg block on a horizontal frictionless surface is attached to an ideal massless spring whose spring constant is 150 N/m. The block is pulled from its equilibrium position at x = 0.00 m to a displacement x = +0.080 m and is released from rest. The block then executes simple harmonic motion along the horizontal x-axis. When the displacement is x = 0.024 m, what is the kinetic energy of the block?
Answer:
The kinetic energy is ![KE = 0.4368\ J](https://tex.z-dn.net/?f=KE%20%3D%200.4368%5C%20%20J)
Explanation:
From the question we are told that
The mass of the block is ![m= 0.025\ kg](https://tex.z-dn.net/?f=m%3D%200.025%5C%20kg)
The spring constant is ![k = 150 N/m](https://tex.z-dn.net/?f=k%20%3D%20150%20N%2Fm)
The length of first displacement is ![x_1 = 0.80 \ m](https://tex.z-dn.net/?f=x_1%20%3D%200.80%20%5C%20m)
The length of first displacement is ![x_2 = 0.024 \ m](https://tex.z-dn.net/?f=x_2%20%3D%200.024%20%5C%20m)
At the
the kinetic energy is mathematically evaluated as
![KE = \Delta E](https://tex.z-dn.net/?f=KE%20%20%3D%20%5CDelta%20E)
Where
is the change in energy stored on the spring which is mathematically represented as
![\Delta E = \frac{1}{2} k (x_1 ^2 - x_2^2)](https://tex.z-dn.net/?f=%5CDelta%20E%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20k%20%28x_1%20%5E2%20-%20x_2%5E2%29)
=> ![KE = \frac{1}{2} k (x_1 ^2 - x_2^2)](https://tex.z-dn.net/?f=KE%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20k%20%28x_1%20%5E2%20-%20x_2%5E2%29)
Substituting value
![KE = \frac{1}{2} * 150 * (0.08^2 - 0.024^2)](https://tex.z-dn.net/?f=KE%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%2A%20150%20%2A%20%20%280.08%5E2%20-%200.024%5E2%29)
![KE = 0.4368\ J](https://tex.z-dn.net/?f=KE%20%3D%200.4368%5C%20%20J)
Potential.
At the top of a pendulum's swing, the ball is no longer moving (at that very specific point of time). All of its kinetic energy has been converted to potential energy (or more specifically in this instance, gravitational potential energy).
Answer:
Its state is in uniformly accelerated motion
Explanation:
When an object is acted upon the force of gravity only, we said that the object is in free fall.
According to Newton's second law of motion:
![F=ma](https://tex.z-dn.net/?f=F%3Dma)
where F is the net force on an object, m is its mass, a its acceleration, when the net force on an object (F) is non-zero, than the object accelerates (because a is non-zero), so the object is in accelerated motion.
In case of free fall, the rate of acceleration of the object is equal to
, the acceleration due to gravity, and it is constant. So, the object is moving by uniformly accelerated motion.