Potential energy of spring, conservation of mechanical energy, conservative and non-conservative forces
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See all →- The potential energy of a long spring when stretched by 2 cm is U. If the spring is stretched by 8 cm, potential energy stored in it will be : Answer: 1. 16U Spring energy U=1/2kx²∝ x² . Extension goes from 2 cm to 8 cm, a factor of 4, so energy goes up by 4²=16 . The new energy is... 1
- A particle is released from height S from the surface of the Earth. At a certain height its kinetic energy is three times its potential energy. The height from the surface of earth and the speed of the particle at that instant are respectively : Answer: 4. S/4, √(3gS/2) Key idea: total mechanical energy mgS is conserved (taking the surface as zero of potential energy). At height h: U... 1