A gymnast of mass 66.0 kg hangs from a vertical rope attached to the ceiling. you can ignore the weight of the rope and assume that the rope does not stretch. use the value 9.81m/s2 for the acceleration of gravity.

Respuesta :

The question is incomplete.


These are the parts missing.


Part A:


Calculate the tension T in the rope if the gymnast hangs motionless on the rope.


Express your answer in newtons.


Part B:


Calculate the tension T in the rope if the gymnast climbs the rope at a constant rate.


Express your answer in newtons.


Part C:


Calculate the tension T in the rope if the gymnast climbs up the rope with an upward acceleration of magnitude 1.50 m/s2 .


Express your answer in newtons.


Part D:


Calculate the tension T in the rope if the gymnast slides down the rope with a downward acceleration of magnitude 1.50 m/s2 .


Express your answer in newtons.



Answer:


This is how you answer each part.


Part A:


Calculate the tension T in the rope if the gymnast hangs motionless on the rope.



The acceleration is zero, so the net force is 0:


T - mg = 0


T = mg = 66kg × 9.81 m/s² = 647.46 N


Part B:


Calculate the tension T in the rope if the gymnast climbs the rope at a constant rate.


The acceleration is zero too, so yet the tension is T = 647.46 N


Part C:


Calculate the tension T in the rope if the gymnast climbs up the rope with an upward acceleration of magnitude 1.50 m/s2 .


Now the acceleration of the gymnast is 1.50m/s², so she is adding a force of ma, which turns the equation into:


T - mg = ma


T = mg + ma = m (g + a) = 66kg (9.81 + 1.5)m/s² = 746.46N


So, the new tension is T = 746.46N


Part D:


Calculate the tension T in the rope if the gymnast slides down the rope with a downward acceleration of magnitude 1.50 m/s2 .


Now, the acceleration is downward so it has the opposite sign of that of the part C.


T = m(g -a) = 66 kg (9.81 - 1.5)m/s² = 548.46


The new tension is T = 548.46N