Question

4. Two forces act on a 2 kg object as shown. What is the magnitude of the acceleration of the object?

(A) 7 m/s2
(B) 5 m/s2
(C) 3.5 m/s2
(D) 0.4 m/s2

Answer 1

The resultant force on the object is

∑ F = 〈0, 8〉 N + 〈6, 0〉 N = 〈6, 8〉 N

which has a magnitude of

F = √((6 N)² + (8 N)²) = √(100 N²) = 10 N

By Newton's second law, the acceleration has magnitude a such that

F = m a

10 N = (2 kg) a

a = (10 N) / (2 kg)

a = 5 m/s²

so the answer is B.