Question

A child is pulling block of mass M = 5 kg on a rough surface

with a force of F1 = 30 N at an angle of θ = 30° to the

horizontal axis. The friction force F2 = 10 N.

Find out magnitude of resultant force

Draw the resultant force.

Answer 1

Given

Applied force $F_1=30 N$

Frictional force $F_2=10 N$

The resultant force is

$R=\sqrt{(F_1^2+F_2^2+2F_1F_2cos150^o)}=\sqrt{((30)^2+(10)^2+2(30)(10)cos150^o)}=480 N$

Diagram: