5 kg block of iron is heated to 800°C. It is placed in the tub containing 2 L of water at 15°C. Assuming all the water is brought to the boil rapidly, calculate the mass of water which boils off. (The specific heat capacity of iron 800°C is 220 J kg-1 K-1)

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.

What is the final velocity of the initial velocity of 25 and -50?