Newton's 2nd law of motion: Force = (mass) x (acceleration)
If you want to move a 7-kg object with an acceleration of 6 m/s²,
then you will need to push it with (7 x 6) = 42 newtons of force.
You don't mean the force of an object.
Answer:
<em>8hours 45minutes</em>
Explanation:
Amount of heat energy used up by the electric substance = heat gained by the water.
Amount of heat energy used up by the electric substance = Power * Time
heat gained by the water. = mcΔt
m is the mass of the water in kg
c is the specific heat capacity
Δt is the change in temperature
Given parameters
Power = 5kW = 5000W
mass of water m = 500kg
c = 4200J/kgC
Δt = 100°C - 25°C = 75°C
Required
Time taken
Substituting the given parameters into the formula
Pt = mcΔt
5000t = 500*4200*75
5000t = 157,500,000
Divide both sides by 5000
t = 157,500,000/5000
t = 31,500 secs
t = (31,500/3600)hrs
t = 8.75hours
t = 8hours 45minutes
<em>Hence it takes 8hours 45minutes to heat 500 kg of water in the tank from 25c to 100c</em>
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