The mass of a subway car and passengers is 40,000 kg. If its acceleration as it leaves a station is 0.9 m/s2, what is the net force acting on it?

Answer body lying face up ;

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.

Ansa new gas is observed in the form of bubbles;