What force is needed to accelerate a 90 kg punching bag 13 m/s2?

According to the law of conservation of mass, in a chemical reaction the total starting mass of all the reactants equal the total final mass of all the products. true or false?

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

Two conductors, a and b, are each in the shape of a tetrahedron. but of different sizes. they are charged in the following manner: 1. tetrahedron a is charged from an electrostatic generator to charge q. 2. tetrahedron a is briefly touched to tetrahedron b. 3. steps 1 and 2 are repeated until the charge on tetrahedron b reaches a maximum value. if the charge on tetrahedron b was q/4 after the first time it touched tetrahedron a. what is the final charge qbmax on tetrahedron b?