A force of 300N is used to stretch a horizontal spring with a 0.5kg block attached to it by 0.25m. the block is released from rest and undergoes harmonic motion. Calculate spring constant mechanical energy applied and velocity when x=15cm?​

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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.

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