a body is shot up along an inclined plane which makes an angle of 58 degrees with the vertical. In 15 seconds the body tends to move back down the plane

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.