Question

A heater is rated at 350 W. How long will it take to heat a 250 mL cup of water from 20 C to 50 C?

Answer 1

what i know:
W = Pt so W = 350t
ΔT = 30 C
V = 250 mL

Answer 2

@jkp269

Answer 3

This is the work they have:
We find the time from
ΔQ = mc ΔT;
(350 W)t = (250 mL)(1.00 g/mL)(10–3 kg/g)(4186 J/kg · C°)(50°C – 20°C), which gives t = 90 s.

Answer 4

That's right.

Find the quantity of energy required to heat the water. [J]

Then find the time it will take for the heater to generate that much energy. [W = J/s]