Thank you for your question!
Yes, P=E/time is a formula you could use to solve this problem. However, you will also need to use...
P=U•ILegend :
P : power (W)
U : voltage (V)
I : amperage (I)
...and also...
$ 1\:W•1\:h = 3600\:J ...and finally...:
Q=mc∆TLegend :
Q : energy (J)
m : mass (g)
c : specific heat capacity (J/(g•°C))
∆T : temperature variation (°C)
Therefore, the solution to the problem should look like this :
First, find the power of the hot plate using P=UI. Don't forget to multiply the end result to take into account its energetic efficiency.
Next, find the energy required to bring the water to boiling point using Q = mc∆T. You may have to look around to find the quantity of water being boiled as well as its initial temperature. Remember that, for water, 1 mL = 1 g. The final value of Q is the same variable as E.
Finally, use P = E/t to determine the amount of time required to boil the water. Be careful to remember that 1 W = 1 h • 3600 J.
Don't hesitate to ask for more help!
