When an object is heated, the molecules that make up the object

(a)

begin to move faster

(b)

lose energy

(c)

become heavier

(d)

become lighter

The unit of heat is

(a)

newton

(b)

joule

(c)

volt

(d)

celsius

One litre of water at 30^o C is mixed with one litre of water at 50^o C. The temperature of the mixture will be

(a)

80^o C

(b)

More than 50°C but less than 80^o C

(c)

20^o C

(d)

around 40^o C

An iron ball at 50°C is dropped in a mug containing water at 50^o C. The heat will

(a)

flow from iron ball to water

(b)

not flow from iron ball to water or from water to iron ball

(c)

flow from water to iron ball

(d)

increase the temperature of both