The current Australian foreign exchange at equilibrium is 0.7 US dollar ($US) per Australian dollar. What will happen to the Australian foreign exchange in the two following different scenarios?

a. Each year, much more Australians travel to the United States than Americans travel to Australia. Due to the COVID-19 pandemic, worldwide travelling activities completely stop. elaborate using the concepts of the demand curve for Australian dollars and the supply of Australian dollars.

a. The United States increase its tariffs on Australian exports to the US market. elaborate using the concepts of the demand curve for Australian dollars and the supply of Australian dollars.