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
It can never be shorter than a component - magnitude of avector is the square root of the sum of the components squared, and a square function never produces a negative number. However, it can be the same size as its component, if that component is the only one
1. Acceleration
2. If you are going 12 meters per second and you want to know how many seconds it takes yo get to 105 meters, you need yo find how long it takes to go horizontally then vertically. 12 seconds.
3. B
Answer: Positive
Explanation:
Are you familiar with differential calculus? In a plot of position vs. time, the velocity at any given moment is the derivative at that point. A derivative is just the slope. For this plot, the slope is x/t.
Looking at t = 1s, the slope is 1/1. This means the velocity is a positive 1m/s at time equal to 1 second
