Answer:
22425 J
Explanation:
From the question,
Applying
Q = cm(t₂-t₁).................. Equation 1
Where Q = Thermal Energy, c = specific heat capacity of aluminium, m = mass of aluminium, t₂ = Final Temperature, t₁ = Initial Temperature.
Given: c = 897 J/kg.K, m = 1.0 kg, t₁ = 50 °C, t₂ = 25 °C (The final temperature is reduced by half)
Substitute these values into equation 1
Q = 897×1×(25-50)
Q = 897×(-25)
Q = -22425 J
Hence the thermal energy lost by the aluminium is 22425 J
Ohms Law: V = IR
V is the voltage in volts
I is the current in amps
R is the resistance in Ohms
Rearrange: R = V/I
R = (110)/(0.050)
R = 2200
There are 2200 Ohms of resistance in the circuit.
Answer:
Given
Frequency (f) = 3Hz
Wavelength = 9 m
Speed = ?
Explanation:
we know
Speed = wavelength * frequency
= 9*3
= 27 m/ s
Answer:
t_total = 23.757 s
Explanation:
This is a kinematics exercise.
Let's start by calculating the distance and has to reach the limit speed of
v = 18.8 m / s
v = v₀ + a t₁
the elevator starts with zero speed
v = a t₁
t₁ = v / a
t₁ = 18.8 / 2.40
t₁ = 7.833 s
in this time he runs
y₁ = v₀ t₁ + ½ a t₁²
y₁ = ½ a t₁²
y₁ = ½ 2.40 7.833²
y₁ = 73.627 m
This is the time and distance traveled until reaching the maximum speed, which will be constant throughout the rest of the trip.
x_total = x₁ + x₂
x₂ = x_total - x₁
x₂ = 373 - 73,627
x₂ = 299.373 m
this distance travels at constant speed,
v = x₂ / t₂
t₂ = x₂ / v
t₂ = 299.373 / 18.8
t₂ = 15.92 s
therefore the total travel time is
t_total = t₁ + t₂
t_total = 7.833 + 15.92
t_total = 23.757 s
Answer:
1. Molecular cloud
2. Close binary
3. Brown dwarf
4. Protostellar wind
5. Thermal pressure
6. Protostellar disk
7. Jet
8. Degeneracy pressure
Explanation:
1. The Sun formed, probably along with other stars, within a large molecular cloud.
2. A Close binary consists of two stars that orbit each other every few days.
3. A Brown dwarf is a "star" so small in mass that its core never gets hot enough to sustain nuclear fusion reactions.
4. Most of the gas remaining from the process of star formation is swept into interstellar space by a protostellar wind.
5. As a protostar's internal temperature increases, its growing thermal pressure helps slow its contraction due to gravity.
6. Planets may form within the protostellar disk that surrounds a forming star.
7. Mass can be lost through a jet of material ejected along a protostar's axis of rotation.
8. A "star" with mass below 0.08 solar mass has its gravitational contraction halted by degeneracy pressure.
