Answer:
12 kg
Explanation:
Momentum before collision = momentum after collision
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
After the collision, they have the same velocity, so v₁ = v₂ = v:
m₁ u₁ + m₂ u₂ = m₁ v + m₂ v
m₁ u₁ + m₂ u₂ = (m₁ + m₂) v
We know that m₁ = 6 kg, u₂ = 0 m/s, and v = u₁ / 3.
(6 kg) u₁ + m₂ (0 m/s) = (6 kg + m₂) (u₁ / 3)
(6 kg) u₁ = (6 kg + m₂) (u₁ / 3)
6 kg = (6 kg + m₂) (1/3)
18 kg = 6 kg + m₂
m₂ = 12 kg
Answer:
Total heat transfer is positive
Total work transfer is positive
Explanation:
The first law of thermodynamics states that when a system interacts with its surrounding, the amount of energy gained by the system must be equal to the amount of energy lost by the surrounding. In a closed system, exchange of energy with the surrounding can be done through heat and work transfer.
Heat transfer to a system is positive and that transferred from the system is negative.
Also, work done by a system is positive while the work done on the system is negative.
Therefore, from the question, since the heat engine inputs 10kJ of heat, then heat is being transferred to the system. Hence, the sign of the total heat transfer is positive (+ve)
Also, since the heat engine outputs 5kJ of work, it implies that work is being done by the system. Hence the sign of the total work transfer is also positive (+ve).
The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.
A pressure system is a relative peak or lull in the sea level pressure distribution. The surface pressure at sea level varies minimally, with the lowest value measured 87 kilopascals (26 inHg) and the highest recorded 108.57 kilopascals (32.06 inHg). High- and low-pressure systems evolve due to interactions of temperature differentials in the atmosphere, temperature differences between the atmosphere and water within oceans and lakes, the influence of upper-level disturbances jargon as well as the amount of solar heating or radiational cooling an area receives. Pressure systems cause weather experienced locally. Low-pressure systems are associated with clouds and precipitation that minimize temperature changes through the day, whereas high-pressure systems normally associated with dry weather and mostly clear skies with larger diurnal temperature changes due to greater radiation at night and greater sunshine during the day. Pressure systems are analyzed by those in the field of meteorology within surface weather maps.
