One end of a spring of negligible mass is attached to the ceiling. When a 250 g mass is placed on the free end (without stretching the spring) and then released, the mass descends 20.0 cm before it changes direction and begins to ascend. What is the spring constant k (in N/m)

The softest and hardest minerals are: softest hardest

How many neutrons does plutonium -196 with an atomic number of 78.

What accounts for an increase in the temperature of a gas that is kept at constant volume? a. energy has been removed as heat from the gas. b. energy has been added as heat to the gas. c. energy has been removed as work done by the gas. d. energy has been added as work done by the gas.