Answer:
V_vap = 161.2 L
Explanation:
The total mass of the aluminum rod is given as;
m = ρ∙V = ρ∙L∙A
Where;
ρ is density = 2700 kg/m³
L is length = 3.3m
A is cross sectional area = 3.8 cm² = 3.8 x 10⁻⁴ m²
Thus;
m = 2700kg/m³•3.3m•3.8 × 10⁻⁴m²
= 3.3858kg
By cooling down the submerged half of the aluminum rod releases an heat amount of
Q = (1/2)∙m∙cp∙∆T
Where;
cp is specific heat of aluminum aluminum = 900 J/kg
∆T is change in temperature = 274 - 4.2 = 269.8 K
Thus;
Q = (1/2)•3.3858•900•(269.8)
= 411069.978 J
The liquid absorbs this heat and vaporizes partially, such that the heat equals vaporized mass times latent heat of vaporization:
Q = m_vap•∆h_vap
Making m_vap the subject;
m_vap∙ = Q/∆h_vap
Where ∆h_vap is latent heat of vaporization given as 20900J/kg
Thus,
m_vap∙ = 411069.978/20900
= 19.668 kg
Let's divide this mass by the density of liquid helium and we get the liquid volume which has vaporized:
V_vap∙= m_vap/ρ
V_vap∙ = 19.668/122
V_vap∙ = 0.1612 m³
Converting to litres;
V_vap = 0.1612 x 1000
V_vap = 161.2 L
A constant force of 1.25N
Explanation:
This is a kinematics problem.
First find acceleration,
then use F = ma to find force.
Given:
mass = .5kg
delta x = 20m
t = 4s
a = ?
Friction = 0
From the kinematics equations:
delta x = Vi + (1/2)at^2
Plug in terms that are given:
20m = 0 + (1/2)a(4^2)
(2*20m)/(16s^2) = a
40m/(16s^2)= 2.5m/s^2
Now use F = ma to find force exerted on object.
F = (0.5kg)*(2.5m/s^2)
F = 1.25N
<span>A vector which implies that an
object has been moved or has changed its position is called displacement.
Displacement is usually associated with length and direction of an imaginary
straight point. It is the shortest distance from the initial point to the final
point of final position (P). Displacement can also be described as the length
between the final and initial point on the shortest path. It means an overall change
in direction of the object or point of a
body.</span>
Answer:
parallel circuit
Explanation:
In a parallel circuit, the potential difference across each of the resistors that make up the circuit is the same. This leads to a higher current flowing through each resistor and subsequently the total current flowing through all the resistors is higher.
