B is true, however that is not a way in which conserving and recycling paper helps manage energy sources...
The upward force of the chain on the diamond would be the tension in the chain, and this tension would have to support the weight of the 45g that hangs from the chain.
mass = 45 g = 45/1000 kg = 0.045kg
Weight = mg = 0.045 * 10 ≈ 0.45N, g ≈ 10 m/s²
So the upward force is ≈ 0.45N.
<span> A reaction in which energy is absorbed from the surroundings is called an endothermic reaction. In endothermic reactions the enthalpy of the products is greater than the enthalpy of the reactants. Exothermic reactions heat up their surroundings while endothermic reactions cool them down.
I hope this helps you </span>
