energy,power and work machines Flashcards
power units
watts (w) how much energy/amount of energy transferred per second like light
So a 60W bulb is burning 60 Joules of energy every second you have it turned on.
kw=
a thousand watts
1w=
1 joule per second
if an oven has 120w
how much energy does it transfer per sec
120 joules
to find either the energy-joules
power-watts
or time -seconds
what do you do?
power-energy divided by time
time- energy divided by power
energy-power times time
E
P T
what is the equation to calculate how much electricty used?
watts times hours time 1kw per hour
what is work in energy?
work done is energy transferred
how do you find out how much work is done?
E
F D
energy divided by force=distance
energy divided by distance=force
force times distance=energy
how do you find out how much work is done?
E
F D
energy divided by force=distance
energy divided by distance=force
force times distance=energy
convert the cm from the distance into metres and joules to kilohjoules
equation to find energy power or time
equation to find how much work is done
ept
efd
how would you convert
cm
j
cm-metres
1j-1kj
what is a simple machine?
a simple machine is something which makes a job easier by reducing the force required to do it e.g can opener
lever-
a bar that rests and moves around a pivot
e.g like a seesaws ,wheelbarrows, scissors, pilers, bottlle opener
what is a force multiplier?
levers are simple machines that act as a force multiplier
makes a small force applied at one end to produce a big force
e.g a bottle opener,scissors,doorknob
more energy you put in=
more energy you get out
