Find the scaler product of this two vector

How much heat is required to convert 0.3 kg of ice at 0°c to water at the same temperature

Using a wheel and axle, a farmer is trying to lift a bucket of water from the bottom of a well. the larger wheel has a radius of 40 cm compared to the axle that has a radius of 10 cm. if a bucket of water is 50 n, then how much effort is required to raise it? 12.5 n 200 n 2 n 500 n

Decreased sensitivity to an unchanging stimulus is known as