+956 A force of magnitude 5 N acts on an object. A second force of magnitude 7 N acts at 50° to the other force. What is the magnitude of these two forces?
a) 8.6 N
b) 10.91 N
c) 11.6 N
d) 12 N
+128408 Let the first vector lie along the x axis
Its components are :
5cos 0° = 5
5 sin 0° = 0
For the second vector we have
So..its components are
7 cos 50° and
7 sin 50°
So....the sum of the components is
5 + 7 cos 50° = 5 + 7 cos 50° and
0 + 7 sin 50° = 7sin 50°
So...the magnitude of the resultant vector is given by sqrt [ ( 5 + 7 cos 50°)^2 + ( 7sin 50°)^2 ] ≈ 10.91 N
