Question 7
Two threads tied to a trolley on a table are held parallel and pulled, and the resultant produced is 20 N. If the force applied to thread A is 12 N, what is the force applied through thread B?
The right answer is the one marked above.
8 N. resultant = A + B, so 20 N = 12 N + B, giving B = 20 N − 12 N = 8 N.
32 N comes from adding 20 and 12 — but 20 N is already the sum, so nothing should be added to it. A subtraction happens here, yet that does not mean the two forces oppose each other.