Quanto vale a resultante de duas forças de mesmo módulo mesma direção e sentidos opostos atuando sobre um corpo de massa igual a 2 kg qual é o valor da aceleração desse corpo nessas condições

This question is in Portuguese, this means:

"How much is the result of two forces of the same module in the same direction and opposite ways acting on a body with a mass equal to 2 kg? what is the value of the acceleration of that body in these conditions?"

Now, i will answer in English.

When we are doing math with forces, we can use "Linear overlay", this means that we can add an subtract the forces between them.

Now, if you apply two forces of the same magnitude and same direction but in opposite ways (one is pointing in x positive and the other in x negative) we can directly add them:

F*(+x) + F(-x) = F(+x) - F(+x) = 0

Where (+x) and (-x) refer to the direction at which the forces are applied,

and it has sense, if you pull with the same force by opposite sides, the total force that the object suffers is zero.

And because the total force that the object suffers is zero, by the second Newton's equation f*m = a, the acceleration that the object suffers is also zero.

if you already have the answer to (a), then just work out how many periods there are in 1 minute, and that's the answer to (c).