Question

3. The boy tries to move the washing machine. a) Calculate the value of the force N of the floor reaction when it is known that the mass of the washing machine is 200 kg. The force of gravity is calculated by the formula G = mg and g = 10 N / kg. b) Calculate the value for the friction force of rest f, when it is known that the boy pushes the washing machine in the horizontal direction with the force F = 300 N. 

Answer 1

a)

$$N=mg=200\ kg\cdot10\ \dfrac{N}{kg}=2000\ N.$$

b)

$$F-F_{fr}=0,$$ $$F_{fr}=F=300\ N.$$