11. a physical therapist is using a wide elastic band to a
patient strengthen his knee after surgery. at the patient's
current stage of therapy, he should not exert more than 20
kilograms weight of force. the band being used for this
therapy exerts a force of 40 grams of weight for every
millimeter it is extended. the relationship between force
applied and the distance the band is extended is linear.
what is the maximum distance the therapist should allow
the patient to extend the band?
(a) 5 millimeters
(b) 5 centimeters
(c) 5 decimeters
(d) 80 centimeters