Answer:
The average rate of energy transfer to the cooker is 1.80 kW.
Explanation:
Given that,
Pressure of boiled water = 300 kPa
Mass of water = 3 kg
Time = 30 min
Dryness friction of water = 0.5
Suppose, what is the average rate of energy transfer to the cooker?
We know that,
The specific enthalpy of evaporate at 300 kPa pressure


We need to calculate the enthalpy of water at initial state


We need to calculate the enthalpy of water at final state
Using formula of enthalpy

Put the value into the formula


We need to calculate the rate of energy transfer to the cooker
Using formula of rate of energy

Put the value into the formula


Hence, The average rate of energy transfer to the cooker is 1.80 kW.
Friction is a force. A resistance force that tries to slow down and stop objects in motion. The difference between friction and air resistance is that friction acts on surfaces. For example, if I were skateboarding on a rough surface, more friction would occur so I would travel slower. If I were skareboarding on ice, I would go faster because there is much less friction to slow me down. Hope that helps:)
It rises till all of its Kinetic energy is converted into potential energy.
so, mgh=(1/2)m(v^2)
so, h=(v^2)/2g = 12*12/(2*9.81)=7.34 m
The weight is 45 N, because the three chains hold the sign, and each contributes 15 N.
Notice that the mass would be the weight/acceleration of gravity, m = 45/9.8 kg. But they ask the weight (force, so Newtons)
The CORRECT answer would be false. They are different and so therefore the answer is false.
Hope this helped ‼️