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A 0.279-kg volleyball approaches a player horizontally with a speed of 12.1 m/s. The player strikes the ball with her fist and causes the ball to move in the opposite direction with a speed of 21.5 m/s.
(a) What impulse is delivered to the ball by the player? (Take the direction of final velocity to be the positive direction. Indicate the direction with the sign of your answer.)
___ kg · m/s
(b) If the player's fist is in contact with the ball for 0.0600 s, find the magnitude of the average force exerted on the player's fist.
___ N
Calculate the magnitude of the linear momentum for the following cases.
(a) a proton with mass 1.67 10-27 kg, moving with a speed of 5.85 106 m/s
___kg · m/s
(b) a 14.5-g bullet moving with a speed of 455 m/s
___kg · m/s
(c) a 74.0-kg sprinter running with a speed of 12.5 m/s
___kg · m/s
(d) the Earth (mass = 5.98 1024 kg) moving with an orbital speed equal to 2.98 104 m/s.
___ kg · m/s
450
A turbine operates under steady flow conditions, receiving steam at the following state: pressure 1200 kPa, temperature 188 degrees C, enthalpy 2785 kJ/kg, speed 33.3 m/s and elevation 3 m. The steam leaves the turbine at the following state; pressure 20 kPa, enthalpy 2512 kJ/kg, speed 100 m/s and elevation 0 m. Heat is lost to the surroundings at the rate of 0.29 kJ/s. If the rate of steam flow through the turbine is 0.42 kg/s, what is the power output of the turbine in kW?
An inventor claims to have invented a machine that is capable of manufacturing 50 jg / min of ice at -4 °C, from water at 20 °C and 1 bar of pressure, with an electrical energy consumption of kW (exergy). determine a) the heat flux that must be extracted to produce this ice flux, b) the optimal useful work of the process, c) if this machine is possible or not, d) if the machine is possible, the efficiency of the second law of it. the environment is at 20 °C and 1 bar
Water enters the condenser at 30oC which has a mass of 10 kg/s. If heat added is 100 kW, determine the outlet temperature in KJ/s.
0C until its temperature reaches 600
K and pressure reaches at 150 kPa. Determine the change in internal energy, the change in enthalpy,
the heat supplied and the work done in the following processes:
1. Constant Volume Process followed by Constant PressureProcess
2. Constant Pressure process followed by Constant VolumeProcess
Assume that air is an ideal gas. R=8.314 KJ/Kmol K, Cp=20.785 KJ/Kmol K and Cv =20.785
KJ/Kmol KMolecular weight of air =29. B = 42
0C until its temperature reaches 600
K and pressure reaches at 150 kPa. Determine the change in internal energy, the change in enthalpy,
the heat supplied and the work done in the following processes:
1. Constant Volume Process followed by Constant PressureProcess
2. Constant Pressure process followed by Constant VolumeProcess
Assume that air is an ideal gas. R=8.314 KJ/Kmol K, Cp=20.785 KJ/Kmol K and Cv =20.785
KJ/Kmol K.Molecular weight of air =29. B = 42
A turbine operates under steady flow conditions receiving steam at the following state: pressure 1.2 MPa, temperature 188 C, enthalpy 2785 kJ/kg, velocity 33.3 m/s and elevation 3m. The steam leaves the turbine at the following state: pressure 20 kPa, enthalpy 2512 KJ/kg, velocity 100 m/s and elevation 0 m. . Heat loss to the surroundings is at a rate of 0.29 kJ/s. If the rate of steam flow through the turbine is 0.42 kg/s, what is the power output of the turbine in kW?
