1W= ? J (Phyics)

They are different units.
Watt is the unit for Power(功率)
Joule is the unit for Energy(能量)
The relationship between Power and Energy is :
Power Consumed = Energy supplied / Time of supplies
i.e. 1 Watt = 1 Joule / 1 second
( 1W = 1J/s )

For example, a lamp bulb is 40W, to light it up for 10 seconds requires :
= 40W x 10s
= 400J
and, a supplies provides totally 500 000J energy to a machine work for 20seconds, the power consumed for the machine is :
= 500 000J / 20s
= 25 000J
= 25kJ

So, they are different units to describe different forms of physics measurements. It is impossible to make any equivalent between them.

Are you sure that this is the full question? Beacuse 1 watt should equal to 1 Joule per second (1W = 1J/s).