What do f = SP, s and P stand for in science

What do f = SP, s and P stand for in science

S is the stress area, P is the pressure, f = SP should be a pressure formula

Science. Urgent
1. There is an electrical appliance that has been powered on for 10 minutes, and the work done by the current is 3 * 10 ^ 5J. The electrical power of the electrical appliance is ()
2. The current of the fluorescent lamp in the classroom is about 0.18 A. how much work does the current do when it is powered on for 10 minutes?

1、P=W/t=3×10^3J/600s=5w
2、W=UIt=220V×0.18×600s=23760J

Science, urgency
1. What is the actual power of a small bulb marked with 36V 40W when the current passing through it is 1A?
2. The power of an electrical appliance is 1000W. How much energy does it consume when it works for one hour?

1. First, calculate the resistance R = 36 * 36 / 40 = 32.4 with r = u ^ 2 / P, and then get the actual power P1 = 1 * 1 * 32.4 = 32.4w according to the power = I ^ 2 * r
2. 1H = 3600s, so w = 1000 * 3600 = 3600000j = 1kwh is obtained by using w = Pt