A window washer pulls herself upward using the bucket-pulley apparatus. The mass of the person plus the bucket is 69 kg.How hard must she pull downward to raise herself slowly at constant speed?If she increases this force by 11 percent, what will her acceleration be? There is only one pulley.
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To determine the force the window washer must exert to raise herself slowly at a constant speed, we can use Newton's second law of motion, which states that the force applied is equal to the mass multiplied by the acceleration.
First, we need to determine the force required to counteract the force of gravity acting on the window washer and the bucket. The force of gravity can be calculated by multiplying the mass (69 kg) by the acceleration due to gravity (9.8 m/s^2). This gives us a force of 676.2 N acting downward.
Since she is raising herself at a constant speed, we know that the net force acting on her must be zero. This means the force she exerts must be equal to the force of gravity pulling her downward. Therefore, the force she must pull downward is also 676.2 N.
Now, let's consider the second part of the question. If she increases the force by 11 percent, we need to calculate both the new force and the resulting acceleration.
To find the new force, we multiply the original force (676.2 N) by 1.11 (11 percent increase). This gives us a force of approximately 748.98 N.
To calculate the resulting acceleration, we can use the modified force and the mass of the window washer plus the bucket (69 kg). Rearranging Newton's second law of motion, we can solve for acceleration as acceleration = force / mass.
Substituting the values, we get:
acceleration = 748.98 N / 69 kg
acceleration ≈ 10.87 m/s²
Therefore, if the window washer increases her force by 11 percent, her resulting acceleration will be approximately 10.87 m/s².