If the 5,500 J of sound and light is the ONLY useful output
from the phone, then the phone's efficiency is
(5,500J / 10,000J) = 0.55 = 55% .
But the test engineer forgot one little minor almost insignificant detail.
As a test engineer myself, I'd say that he needs to turn in his laptop
and soldering iron, and think about changing his career to a job for
which he may be better suited, like 8 hours a day in a highway toll-booth.
What about that little radio transmitter and receiver inside the phone,
that maintain digital RF communication with the nearest cell tower ?
Without that microscopic radio transceiver ... plus 30 or 40 apps
that are always running unless you shut them off ... the device in your
pocket is essentially a flat rock with one side that sometimes glows.
Answer:
Explanation:
Moment of inertia of the metal rod pivoted in the middle
= M l² / 12
If the spring is compressed by small distance x twisting the rod by angle θ
restoring force by spring
= k x
moment of torque about axis
= k x l /2
= k θ( l /2 )² ( x / .5 l = θ )
=
moment of torque = moment of inertia of rod x angular acceleration
k θ( l /2 )² = M l² / 12 d²θ/dt²
d²θ/dt² = 3 k/M θ
acceleration = ω² θ
ω² = 3 k/M
ω = √ 3 k / M
<h2>
Answer:</h2>
<em>Hello, </em>
<h3><u>
QUESTION)</u></h3>
Assuming that the initial velocity of the jumper is zero, on Earth any freely falling object has an acceleration of 9.8 m/s².
<em>✔ We have : a = v/Δt = ⇔ Δt = v/a </em>
- Δt = (√2xgxh)/9,8
- Δt = (14√10)/9,8
- Δt ≈ 4,5 s
Answer:
Explanation:
Answer:
Explanation:
The half life is the time taken for half of a radioactive substance to disintegrate.
The shorter the half life, the larger the decay constant and the faster the decay process.
For a very large half life, it would take a very long time for the radioactive nuclide to decay to half.
With each half life reached, a new set of daughter cell is formed. Atoms that have short half life would decay rapidly. Every radionuclide has its own characteristic half-life.
If the number of half-lives increases, then the number of radioactive atoms decreases, because approximately half of the atoms' nuclei decay with each half-life. With this observation, we can hypothesise and conduct experiment to support the assertion that as the number of half-lives increases then the number of radioactive atoms decreases.
Answer:
38.3 m/s
Explanation:
To find vertical component of initial velocity, you'd have to use sine ratio:
is vertical component of initial velocity and 
is initial velocity given which is 50 m/s.
A stone is projected at an angle of 50 degrees so 
= 50°. Substitute in the formula:
Therefore, the vertical component of initial velocity is approximately 38.3 m/s
(The picture is also attached for visual reference!)
