A 0.05-m3 rigid tank initially contains refrigerant-134a at 0.8 MPa and 100 percent quality. The tank is connected by a valve to a supply line that carries refrigerant-134a at 1.2 MPa and 40°C. Now the valve is opened, and the refrigerant is allowed to enter the tank. The valve is closed when it is observed that the tank contains saturated liquid at 1.2 MPa. The properties of refrigerant are v1 = 0.02565 m3/kg, u1 = 246.82 kJ/kg, v2 = 0.0008935 m3/kg, u2 = 116.72 kJ/kg, and hi = 108.28 kJ/kg. A) Determine the heat transfer (Q). B) Determine the mass of the refrigerant that has entered the tank.

A= 203 KJ

B= 54 Kg

Explanation:

The initial specific volumes and internal energies are obtained from A-12 for a given pressure and state. The enthalpy of the refrigerant in the supply line is determined using the saturated liquid approximation for the given temperature with data from A-11. The mass that has entered the tank is:

Δm = m₂ – m₁

= V(1/α₂ – 1/α₁)

= 0.05 (1/0.0008935 – 1/ 0.025645)Kg

= 54Kg

The heat transfer is obtained from the energy balance:

ΔU= +  

m₂u₂ – m₁u₂ = +

= m₂u₂ – m₁u₁ –

= V/α₂u₂ - V/α₁u₁ –

=(0.05/0.0008935 . 116.72 – 0.05/0.025645 . 246.82 – 54.108.28) Kj

= 203 KJ

the amount of current in the coil

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.