Answer:
the energy of the spring at the start is 400 J.
Explanation:
Given;
mass of the box, m = 8.0 kg
final speed of the box, v = 10 m/s
Apply the principle of conservation of energy to determine the energy of the spring at the start;
Final Kinetic energy of the box = initial elastic potential energy of the spring
K.E = Ux
¹/₂mv² = Ux
¹/₂ x 8 x 10² = Ux
400 J = Ux
Therefore, the energy of the spring at the start is 400 J.
The time taken by the pulse to travel from one support to the other is 0.208 s.
<h3>Given:</h3>
The mass of the cord is m = 0.65 kg.
The distance between the supports is, d = 8.0 m.
The tension in the cord is T = 120 N.
The time taken by the pulse to travel from one support to the other is given as,


Here, v is the linear velocity of a pulse. Its value is,



Then,


Thus, the time taken by the pulse to travel from one support to the other is 0.208 s.
Learn more about tension here:
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Every person is different. But for a planet-wide overall average that roughly represents all human beings on Earth, the figures usually used are:
from 20 Hz to 20,000 Hz .
Answer:
Approximately
.
Explanation:
This question suggests that the rotation of this object slows down "uniformly". Therefore, the angular acceleration of this object should be constant and smaller than zero.
This question does not provide any information about the time required for the rotation of this object to come to a stop. In linear motions with a constant acceleration, there's an SUVAT equation that does not involve time:
,
where
is the final velocity of the moving object,
is the initial velocity of the moving object,
is the (linear) acceleration of the moving object, and
is the (linear) displacement of the object while its velocity changed from
to
.
The angular analogue of that equation will be:
, where
and
are the initial and final angular velocity of the rotating object,
is the angular acceleration of the moving object, and
is the angular displacement of the object while its angular velocity changed from
to
.
For this object:
, whereas
.
The question is asking for an angular acceleration with the unit
. However, the angular displacement from the question is described with the number of revolutions. Convert that to radians:
.
Rearrange the equation
and solve for
:
.