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.
Larry Finkelstein, Norman Fischer, and Cassius Schwartz have been overlooked, in my opinion.
The sound is increased because sound waves are in fact mech. waves which means the that they can't travel through empty space and thus need a medium to travel through
Remember your kinematic equations for constant acceleration. One of the equations is

, where

= final position,

= initial position,

= initial velocity, t = time, and a = acceleration.
Your initial position is where you initially were before you braked. That means

= 100m. You final position is where you ended up after t seconds passed, so

= 350m. The time it took you to go from 100m to 350m was t = 8.3s. You initial velocity at the initial position before you braked was

= 60.0 m/s. Knowing these values, plug them into the equation and solve for a, your acceleration:
Your acceleration is approximately
.