Answer:
f = 3.09 Hz
Explanation:
This is a simple harmonic motion exercise where the angular velocity is
w² = 
to find the constant (k) of the spring, we use Hooke's law with the initial data
F = - kx
where the force is the weight of the body that is hanging
F = W = m g
we substitute
m g = - k x
k = 
we calculate
k = 
k = 3.769 10² m
we substitute in the first equation
w² = 
w = 19.415 rad / s
angular velocity and frequency are related
w = 2πf
f = 
f = 19.415 / 2pi
f = 3.09 Hz
The experiments that claimed to demonstrate cold fusion were found
to have been faulty by others who reviewed them. Also, nobody else
was
able to reproduce the finding in other laboratories. In the world
of
Science, this pretty much says that the initial claims were unfounded.
Answer: Work W = 0
Explanation: Work W = F·s. Because rock does not move, s = 0 and
work done is zero.
Answer:
I will choose the answer A
Explanation:
A wavefront is the long edge that moves, for example, the crest or the trough. Each point on the wavefront emits a semicircular wave that moves at the propagation speed v. These are drawn at a time t later, so that they have moved a distance s = vt.
