You want to fill up a 10 L mop bucket to mop your floor. Explain conceptually using thermal physics principles whether i

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You want to fill up a 10 L mop bucket to mop your
floor. Explain conceptually using thermal physics principles
whether it uses less energy to boil a 2.0 L kettle and fill the
rest of the bucket with tap water, or to use hot water from the hot
water system to fill the whole bucket.
Assume the tap water is at 20 °C and your hot water system
operates at 60 °C.