Consider the following reaction 2Mg(s) + 02 (9) 2Mgo (s)
If 21.2 kcals of energy is released by this reaction, how many kJ
of energy does the reaction release? (1 cal = 4.184 J) (Round off
decimal to nearest tenths)

//(b) both involve the use of levers;

The boat's velocity relative to the riverbank can be resolved into two components. the component going north is 2.7 m/s and the component going west is 1.2 m/s.we add these two vectors and then find the magnitude of the resultant to get the speed.the magnitude of the resultant vector from adding can be obtained by the pythagorean theorem.    to two significant figures, the boat's speed relative to the riverbank is 3.0 m/s.

Dis the best answer im sure it is it has to be im positive