What is the primary function of earth's atmosphere (1 point)?

How much force must a locomotive exert on a 12840-kg boxcar to make it accelerate forward at 0.490 m/s2?

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)

The voltmeter reads 117 v and ammeter reads 0.13 a .if the resistance of ammeter and voltmeter are 9 kilo ohm and 0.015 ohm respectively ,find the value of r. 3marks