A 600g toy train completes 10 laps of its circular track in 1 min 20s. If the radius of the track is 1.2 m, Find the speed of the train in m/s.

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.