Duas cargas positivas e puntiforme das quais, uma é o triplo da outra, repelem-se a força de intensidade de 2,7N no vácuo, quanto a distância entre elas é de 10cm, determine a menor das cargas

Determine the maximum r-value of the polar equation r =3+3 cos 0

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.