If you double the net force on an object what is the result of the acceleration

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?

M1 = 2.8 kg, m2 = 6.72 kg, m3 = 11.2 kg, byas in .is ,is .toof m3 it 0.91 m. (in m/s)