Answer:
Q = 675 [J]
Explanation:
We can calculate the amount of heat transfer by means of the following expression that includes the mass and temperature change in a body as a function of the specific heat.

where:
m = mass = 25 [gr]
Cp = specific heat = 0.9 [J/g*°C]
Tinitial = 55 [°C]
Tfinal = 25 [°C]
![Q=25*0.9*(55-25)\\Q=675 [J]](https://tex.z-dn.net/?f=Q%3D25%2A0.9%2A%2855-25%29%5C%5CQ%3D675%20%5BJ%5D)
Answer: No , a chemical change has not occured as it was easily reversed.
Explanation:
Chemical change is defined as a change in which rearrangement of atoms take place and leads to formation of new substances. It can only be reversed with the help of a chemical reaction.
Physical change is defined as a change which leads to change in shape, size or state of the substance changes. No new substance is formed.It can be easily reversed.
As the hair colour was washed out and returned to its original brown colour, it was a physical change.
distance from the Sun of 2.77 astronomical units or about 414 million km 257 million miles and orbiting period of 4.62 years