A 50 kg refrigerator is located on a skyscraper that is 250 m above ground. What is the potential energy of the refrigerator?
A) 12,500 joules
B) 5 joules
C) 122,500 joules

Which is an advantage of subdividing science into different areas?

Aplane's average speed between two cities is 600 km/h. if the trip takes 2.5 hours, how far does the plane fly?

In a particular chemical reaction, the energy of the reactants is 30 kj and the energy of the products is 5 kj. 
 the maximum energy of the system is 40 kj. sketch a potential energy diagram for this reaction. make sure to label the energy of the reactants, the energy of the products, the activation energy, and the enthalpy change for the reaction.