What is the cost, in dollars, of heating the hot tub, assuming 75.0% efficiency to account for heat transfer to the surroundings?

$ 5.93

Explanation:

If we are to put into consideration the following factors even though it was not all stated in the question.

What is the cost of heating a hot tub containing 1500 kg of water from 10.0°C to 40.0°C, assuming 75.0% efficiency to take heat loss to surroundings into account? The cost of electricity is ¢8.50/kW·h.

Q = mc∆T 1

Where m is the mass of water = 1500kg

C is the specific heat capacity of water = 4.184

∆T = temperature change

= 40° - 10°

= 30°

Now, substitute the values into equation 1

= 1500×4.184×30

= 188280

Q in kw/s

= 188280/3600

= 52.3kw/hr

Efficiency = 75%

= 75/100

= 0.75

Hence we have

52.3/0.75

= 69.73kw/hr

C = Q × cost per kw/hr

C = 69.73× $8.5/100

C = 5.92705

C =$ 5.93

Hence, the cost of heating the hot tub is $ 5.93

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.