PLEASE HELP The energy diagram shows the change in energy during a chemical reaction. Which statement best describes the total energy change of the system? (IMAGE PROVIDED)

A175 g lump of molten lead at its melting point (327 c) is placed into 55.0 g of water at 20.0 c. the specific heat of lead is 130.j/kg c and the hf of lead is 20,400 j/kg. when the lead and the water have reached equilibrium, what is the temperature of the mixture?

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

Which of the following are appropriate acceleration units?