Question

please it is urgent friends all of these questions class :- 6th lessson:- changes around up please ya​

Answer 1

Answer:

1. A blacksmith heats the metal rim to fix it onto a cart wheel because a metal rim is made slightly smaller. On heating, the rim expands and fits onto the wheel. Then on cooling, the rim contracts and fits tightly onto the wheel.

2. Formation of clouds is a physical change because when water evaporates in the process of evaporation it goes into air and form clouds by the process of condensation . This water goes back to earth by precipitation. This process is repeated again and again.

3. Explosion of a cracker is a chemical change because the explosive reactants are transformed into gaseous products along with heat, light and sound which cannot be reversed. Hence, it is a chemical change.

4. Small gaps which function as expansion joints are deliberately left between the rail ends to allow for expansion of the rails in hot weather. ... Because of these small gaps, when trains pass over jointed tracks they make a "clickety-clack" sound.

Explanation:

Hope it helps you.......