Answer:
The mass of the beam is = 29 kg.
Explanation:
A beam with mass 40 kg is shown in figure. Point S is the support point. Point B is the middle point on the beam where mass of the beam acts.
Taking moment about Point S
40 × 21 = 
× 29
= 29 kg
Therefore the mass of the beam is = 29 kg.
Answer:
<em>according to the conservation of mass,</em>
<em>according to the conservation of mass,the mass of the water is 36.04g</em><em>r</em><em>a</em><em>m</em><em>s</em><em> </em>
Explanation:
Hope It Help you
Answer:
f' = 2 f
Explanation:
The frequency of the pendulum that swings in simple harmonic motion is given by :
Where
l is the length of pendulum
g is the acceleration due to gravity
If the length of the thread is increased by a factor of 4, such that, l' = 4 l, let f' is the new frequency such that,
f' = 2 f
So, the new frequency of the pendulum will become 2 time of initial frequency. Hence, the correct option is (b) "2f"
Missing part in the text of the problem:
"<span>Water is exposed to infrared radiation of wavelength 3.0×10^−6 m"</span>
First we can calculate the amount of energy needed to raise the temperature of the water, which is given by
where
m=1.8 g is the mass of the water
is the specific heat capacity of the water
is the increase in temperature.
Substituting the data, we find
We know that each photon carries an energy of
where h is the Planck constant and f the frequency of the photon. Using the wavelength, we can find the photon frequency:
So, the energy of a single photon of this frequency is
and the number of photons needed is the total energy needed divided by the energy of a single photon:
The second law of thermodynamics states that the state of entropy of the entire universe, as an isolated system, will always increase over time. The second law also states that the changes in the entropy in the universe can never be negative.
