Answer:
The velocity of the star is 0.532 c.
Explanation:
Given that,
Wavelength of observer = 525 nm
Wave length of source = 950 nm
We need to calculate the velocity
If the direction is from observer to star.
From Doppler effect
Put the value into the formula
Negative sign shows the star is moving toward the observer.
Hence, The velocity of the star is 0.532 c.
Answer:
1.84 kJ (kilojoules)
Explanation:
A specific heat of 0.46 J/g Cº means that it takes 0.46 Joules of energy to raise the temperature of 1 gram of iron by 1 Cº.
If we want to heat 50 g of iron from 20° C to 100° C, we can make the following calculation:
Heat = (specific heat)*(mass)*(temp change)
Heat = (0.46 J/g Cº)*(50g)*(100° C - 20° C)
[Note how the units cancel to yield just Joules]
Heat = 1840 Joules, or 1.84 kJ
[Note that the number is positive: Energy is added to the system. If we used cold iron to cool 50g of 100° C water, the temperature change would be (Final - Initial) or (20° C - 100° C). The number is -1.84 kJ: the negative means heat was removed from the system (the iron).
Answer: d boiling water
Explanation: the water is boiling and bubbling cause the molecules are so fast and they hit off each other
Answer:
See below...
Explanation:
Let’s express ⟨α⟩ in terms of ωi , ωf , and Δt. and torque in terms of It , ωi , ωf , and Δt.
STEP 1.
The rate of change of angular velocity is Angular acceleration.
The net change in angular velocity is Average angular acceleration divided by the elapsed time.
⟨α⟩ = ω f −ω i/Δt
STEP 2.
Torque is assumed this way
dω
τ = I ----
dt
.
⟨τ ⟩ = I t (ω f −ω i )/Δt
Answer:
Water.
Explanation:
This means:
1) For the temperature of water to raise at any point to the next degree by 1°C, will require a specific heat capacity of 4.184 J/Kg°C
2) For the temperature of wood to raise at any point to the next degree by 1°C, will require a specific heat capacity of 1.760 J/Kg°C
Note that: specific heat is directly proportional to energy, therefore the higher the heat capacity, the higher the energy.
4.184 J/Kg°C is higher than 1.760 J/Kg°C, hence WATER needs more energy.
