Question

"A window washer pulls herself upward using the bucket-pulley apparatus. The mass of the person plus the bucket is 65 kg.

Answer 1

Part A.

If there is a constant speed, therefore the net force is zero.

Forces acting are the:

1. Weight

2. Upward force exerted by the rope which is opposite in direction but the magnitude is to the force which is acting downwards exerted on the rope.

∑Force = pulling force - weight = 0

Weight = mg

Hence,

F (pulling force) = mg

Substituting the values,

F (pulling force) = 65 × 9.81

F (pulling force) = 637.65 Newton

____________________________________________________________

Part B.

F = ma

10% increase in the force = 1.10 ₓ 637.65

10% increase in the force = 701.415

Therefore,

701.415 = 65 ₓ a

a = 701.45/65

a = 10.8 m/s²

Answer 2

Consider the free body diagrams as shown in the file attached.

Let the acc of system is a.
For the washer T+N-m1g=m1a ............................(1)
For the bucket T-N-m2g=m2a ............................(2)

(A)
a=0 Eqns (1) and (2) become T+N-m1g=0 T-N-m2g=0 Adding and rearranging, T=(m1+m2)/2g T=325N
(B)
We are specified the value of T here as 325+32.5=357.5N eqns (1)and (2) become 357.5+N-m1g=m1a 357.5-N-m2g=m2a Adding, 715-(m1+m2)g=(m1+m2)a

Solve for 'a'