Physics, 13.10.2019 00:00 Haneendye123

Which would show an example of how physical changes are reversible? cutting a gold bar in two peices and then putting the pieces next to eachother. or burning a match and then relighting it. or melting tin and then cooling it into a mold. or combining sodium and chlorine to make the new material of table salt

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Answer from: queengenni

Melting tin and then cooling it into a mold is the process which showing physical changes are reversible.

Explanation:

Physical change:

The physical change is the change of shape, size or state of the substance. by physical change a new substance is formed. The physical change can be reversible.

Chemical change:

The change or rearrangement of atoms is there , the change is called the chemical change. which leads to the formation of new substance.

(A) The physical change which is not reversible is cutting a gold bar into pieces next to each other.

(B)Burning a match and then realigning is a chemical change as new substance are formed.

(C)Melting tin and then cooling it into a mold: This is a physical change and it is reversible as its original state is achieved again.

(D)Combination of sodium and chlorine to make the new material of table salt as it is a chemical change.

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Answer from: smcculleymcculley

melting tin and then cooling it into a mold

Explanation: Physical change is a change in which shape, size or state of the substance is changed and no new substance is formed. Physical changes can be reversed by

Chemical change: When there is a change in rearrangement of atoms which leads to the formation of the new substance.

a) Cutting a gold bar in two pieces and then putting the pieces next to each other: It is a physical change but it is not reversible as original state is not achieved again.

b) burning a match and then relighting it: This is a chemical change as new substances are formed.

c) melting tin and then cooling it into a mold: This is a physical change and is reversible as the original state has been achieved again.

d) combining sodium and chlorine to make the new material of table salt: It is a chemical change. $2Na+Cl_2\rightarrow 2NaCl$

Answer from: Quest

unbalanced force

explanation:

Answer from: Quest

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm

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Which would show an example of how physical changes are reversible? cutting a gold bar in two peice...