When the air under the envelope is heated, the balloon lifts. which of the following statements is true? a) hot air balloons use radiation to rise b) hot air balloons use conduction to rise c) hot air balloons use convection to rise d) hot air balloons use air resistance to rise

What type of light does this light bulb produce most (i. e. at what wavelength does the spectrum have maximum intensity)?

Asap and show ! a 14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earths velocity. earth mass is 6.0 * 10^24 kg. show your work assuming the rock earth system is closed.

Electromagnetic induction. a coil of wire contains n turns and has an electrical resistance r. the radius of each turn is a. initially, inside the coil there exists a uniform magnetic field of magnitude b0 parallel to the axis of the coil. the magnetic field is then reduced slowly. the current induced in the coil is i. how long does it take for the magnitude of the uniform field to drop to zero?