A florescent light tube usually contains what?
A a vacuum
B oxygen
C. Mercury vapor
D. Light emitting diodes

You want to move a heavy box with mass 30.0 kg across a carpeted floor. you pull hard on one of the edges of the box at an angle 30∘ above the horizontal with a force of magnitude 240 n, causing the box to move horizontally. the force of friction between the moving box and the floor has magnitude 41.5 n . what is the box's acceleration just after it begins to move

2.which choice most accurately explains what happens to the bonds between atoms when water changes to steam, and what becomes of the energy added during this phase change? when water changes to steam bonds between molecules are created. after reaching the boiling point, energy is used to change bond strength and change the kinetic energy of the atoms. when water changes to steam bonds between molecules break apart. after reaching the boiling point, energy is used to break bonds, but does not affect the kinetic energy of the atoms. when water changes to steam bonds between molecules are created. after reaching the boiling point, energy is used to break bonds, but does not affect the kinetic energy of the atoms. when water changes to steam bonds between molecules break apart. after reaching the boiling point, energy is used to change bond strength and change the kinetic energy of the atoms.

Acarpenter is driving a 15.0-g steel nail into a board. his 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. half of the kinetic energy of the hammer is transformed into heat in the nail and does not flow out of the nail. what is the increase in temperature of the nail after the three blows that the carpenter needs to drive the nail in completely? the specific heat of steel is 448 j/kg ∙ k. a) 2.7 k b) 1.8 k c) 7.7 k d) 8.1 k e) 3.6 k