Answer:
a) N = 343 [N]
Step-by-step explanation:
We must remember Newton's third law, which tells us that the force acting on a body is equal to the normal reaction force of equal magnitude but acting in the opposite direction.
![N=m*g](https://img.qammunity.org/2021/formulas/physics/high-school/80jbk2r05m12mlldlly7efbuq39vr75ca0.png)
where:
m = mass = 35 [kg]
g = gravity acceleration = 9.81 [m/s²]
![N = 35*9.8\\N= 343 [N]](https://img.qammunity.org/2021/formulas/physics/high-school/owior7jks7ouzqra2wrz3jnriwusvyizh5.png)