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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Answer: long handle
Explanation: they are better for tree planting and other hole-digging. Long shovel handles can reach deep into a hole. And you'll get better leverage, which is easier on your back. ... The lighter the shovel, the easier time you will have digging.
Answer:
2070 m
Explanation:
Find the time to fall from d= 762.5 m to the ground :
d = 1/2 a t^2 shows t = 12.5 s
Horizontal distance = 166 m/s * 15.5 s = 2069.7 m =~2070 m
