They are an example of a positive feedback.
Answer:
I think d is the answer haha
Answer:
the knee extensors must exert 15.87 N
Explanation:
Given the data in the question;
mass m = 4.5 kg
radius of gyration k = 23 cm = 0.23 m
angle ∅ = 30°
∝ = 1 rad/s²
distance of 3 cm from the axis of rotation at the knee r = 3 cm = 0.03 m
using the expression;
ζ = I∝
ζ = mk²∝
we substitute
ζ = 4.5 × (0.23)² × 1
ζ = 0.23805 N-m
so
from; ζ = rFsin∅
F = ζ / rsin∅
we substitute
F = 0.23805 / (0.03 × sin( 30 ° )
F = 0.23805 / (0.03 × 0.5)
F F = 0.23805 / 0.015
F = 15.87 N
Therefore, the knee extensors must exert 15.87 N
The tension in the string when the ball is at the bottom of the path is 2.61 Newtons.
<h3>Tension</h3>
A tension is simply referred to as a force along the length of a flexible medium such as strings, cable, ropes etc.
Tension in a string revolving can be determined using the expression;
T = mv² / r
Where m is mass of object, v is velocity and r is radius ( length of string )
Given the data in the question;
- Radius ( length of string ) r = 97.7cm = 0.977m
- Tension in the string; T = ?
To determine tension in the string, we substitute our given values into the expression above.
T = mv² / r
T = (0.182kg × (3.74m/s)²) / 0.977m
T = (0.182kg × 13.9876m²/s²) / 0.977m
T = (2.5457432kgm²/s²) / 0.977m
T = 2.61kgm/s²
T = 2.61N
Therefore, the tension in the string when the ball is at the bottom of the path is 2.61 Newtons.
Learn more about Tension here: brainly.com/question/14351325
