11
an electrician charges a call-out fee of $40 and $60
per hour.
a. write an expression for the total cost if the
electrician works for h hours
b. how much would it cost if a particular job took
3 hours?
c. use your expression to work out how many hours
the electrician worked for if he charged $400 for a
particular job.

a. 60(h)+40=

b 60(3)+40=

180+40=$220

c. 400=60(h)+40=

  360=60(h) *divide 60 on each side*

   6=h, 6 hours

step-by-step explanation:

we can use this expression to calculate the energy gain as a particle moves with a field or the energy loss as it moves against it. (note that it is also used to define the electron-volt, a unit of energy equal to that gained by an electron as it falls through a pd of 1 v, i.e. w = 1 ev = 1.6 10-19 c 1 v = 1.6 10-19j).in fact this expression is really nothing more than the statement that potential is the potential energy per unit charge. in this case, v= w/qis simply stating that the change in potential energy(or work done) per unit charge is equal to the change in potential (or potential difference), v.student questions: uniform electric fields2electron beamcathode+5 kvanode0 v

570, the answer is 570, hope it