In the context of energy transfers with hot and cold reservoirs, the sign convention is that _______________.
1 answer:
Answer:
B. QC > 0; QH < 0
Explanation:
Given that there are two reservoir of energy.
Sign convention for heat and work :
1.If the heat is adding to the system then it is taken as positive and if heat is going out from the system then it is taken as negative.
2. If the work is done on the system then it is taken as negative and if the work is done by the system then it is taken as positive.
From hot reservoir heat is going out that is why it is taken as negative
From cold reservoir heat is coming inside the reservoir that is why it is taken as positive
That is why the answer will be
,
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Answer:
The speed of transverse waves in the wire is 234.26 m/s.
Explanation:
Given that,
Length of wire = 129 cm
Speed of sound in air = 340 m/s
First position of resonance = 31.2 cm
We need to calculate the wavelength
For pipe open at one end and closed at other, there is node at closed end and an anti node at open end for 1st resonance.
At 1st resonance,
Put the value into the formula
We need to calculate the frequency of sound in pipe
Using formula of frequency
Put the value into the formula
We need to calculate the node distance
For the wire, there are 3 segments, so 4 nodes
Node-node distance ,
We need to calculate the wavelength of the wire
Using formula of length
Put the value into the formula
We need to calculate the speed of the wave
Using formula of frequency
Put the value into the formula
Hence, The speed of transverse waves in the wire is 234.26 m/s.
Answer:
3349J/kgC
Explanation:
Questions like these are properly handled having this fact in mind;
- Heat loss = Heat gained
Quantity of heat = mcΔ∅
m = mass of subatance
c = specific heat capacity
Δ∅ = change in temperature
m₁c₁(∅₂-∅₁) = m₂c₂(∅₁-∅₃)
m₁ = mass of block = 500g = 0.5kg
c₁ = specific heat capacity of unknown substance
∅₂ = block initial temperature = 50oC
∅₁ = equilibrium temperature of block and water after mix= 25oC
m₂= mass of water = 2kg
c₂ = specific heat capacity of water = 4186J/kg C
∅₃ = intial temperature of water = 20oC
0.5c₁(50-25) = 2 x 4186(25-20)
And we can find c₁ which is the unknown specific heat capacity
c₁ = = 3348.8J/kg C≅ 3349J/kg C
Answer:small barrel gun
Explanation:
Given
Muzzle velocity of bullet is greater in short barrel gun as compared to larger barrel gun
acceleration is given by change in velocity with respect to time
In case of short barrel bullet time taken by bullet to reach its muzzle velocity is less therefore acceleration of small barrel bullet is more compared to long barrel bullet.