Answer:
Explanation:
The volumetric expansion of the liquid is given by
where
is the coefficient of volume expansion
is the initial volume
is the change in temperature
For the liquid in this problem,
So we can solve the equation to find :
Answer:
The centripetal force acting on the car is proportional to the mass of the car.
Explanation:
Let,
The mass of the car be 'm'
The velocity of the car moving in the curved path be 'v'
The radius of the curved path be 'r'
According to physics, a body moving ion circular path experience a force directed along the radius of the path. This force is called centripetal force.
The formula for centripetal force is,
<em>F = mv²/r</em>
Where,
a = v²/r
So, if the mass of the car changes, the centripetal force also changes proportionally according to the above equation.
Answer:
Explanation:
Incandescent bulbs are extremely inefficient because 90% of the energy is wasted as heat, with only 10% being converted to visible light. This gives incandescent bulbs a luminous efficiency rating of around 2%. Ultimately, incandescent bulbs perform better as heaters than as light sources.
Answer:
10⁻¹² W / m²
Explanation:
The feeble sound that a man can hear is of the vale which measures 0 on decibel scale . The intensity of sound in terms of J / m² .s is 10⁻¹² W / m² .
So the intensity of sound of monkey at 2.5 km must be 10⁻¹² W / m² .
Answer:
a) P=0.25x10^-7
b) R=B*N2*E
c) N=1.33x10^9 photons
Explanation:
a) the spontaneous emission rate is equal to:
1/tsp=1/3 ms
the stimulated emission rate is equal to:
pst=(N*C*o(v))/V
where
o(v)=((λ^2*A)/(8*π*u^2))g(v)
g(v)=2/(π*deltav)
o(v)=(λ^2)/(4*π*tp*deltav)
Replacing values:
o(v)=0.7^2/(4*π*3*50)=8.3x10^-19 cm^2
the probability is equal to:
P=(1000*3x10^10*8.3x10^-19)/(100)=0.25x10^-7
b) the rate of decay is equal to:
R=B*N2*E, where B is the Einstein´s coefficient and E is the energy system
c) the number of photons is equal to:
N=(1/tsp)*(V/C*o)
Replacing:
N=100/(3*3x10^10*8.3x10^-19)
N=1.33x10^9 photons
