Question

For a moving object, the force acting on the object varies directly with the object's acceleration. When a force of 72 N acts on a certain object, the acceleration of the object is 9m/s^{2} . If the acceleration of the object becomes 5 /ms2 , what is the force?

Answer 1

40N

Explanation:

F=ma

1st case: 72N = m(9m/s^2)

m = 72N/(9m/s^2)

2nd case: F = m(5m/s^2)

m = F/(5m/s^2)

Since the mass is the same:

72N/(9m/s^2) = F/(5m/s^2)

F = 72N/(9m/s^2)/(5m/s^2)

F = (5/9)(72N)

F = 40N