The closest stars are 4 light years away from us. how far away must you be from a 854 khz radio station with power 50.0 kw for there to be only one photon per second per square meter? assume that the photons spread out spherically. the area of a sphere is .
c-how they are used. an incline plane is used as a ramp and a wedge is used in between something.
an object can only accelerate when the forces acting on it are unbalanced.
when that happens
-- the object's speed increases, or
-- its speed decreases, or
-- the direction of its motion changes.
you expect to have heat energy, electrical energy, and mechanical energy involved when you iron your clothes.
you don't expect chemical energy to show up, and if it does, it may ruin some of your clothes.
electricity is also hot so anything that conducts heat must be able to conduct electricity as well