Answer:
Backwards
Explanation:
Friction always acts in the direction opposing motion so if the motion of the wagon is forward, friction acts backwards.
I think the correct question would be, how do you measure sound. :)
you measure sound by using amplitude. It measures how forceful the sound is.
Thats how you know whether its loud or quite :)
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Answer:
here you go
Explanation:
Why do your lights actually come on almost instantaneously? ... Wiring the house in parallel does not make a difference – there is no current flowing through the light bulb when the switch is off no matter how the house is wired. If there were a current already, the light would be on!
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
