The only definite number we can tell you is that in order to lift
a 100kg box, you have to somehow provide a force of about
980 newtons (about 220 pounds) pointing upward. That's the
weight of the box, and you have to lift with at least that much force
just to get the box off the ground.
After that, the answer to your question is 'YES'. The time it takes
depends on how much force you have available, how far you want
to lift the box, and how fast.
Here are the Physics formulas you have to use:
-- The amount of "Work" you'll do is
(the amount of force you use) times (how far up you lift the box) .
-- The "Power" (amount of watts) you'll use is
(the amount of 'work' you do) divided by (the length of time it takes).
So ...
-- The higher you lift the box, the more 'work' your lift-machine does.
-- The faster the box is lifted, the more 'power' your lift-machine needs.
Answer;
- June 21
At 45 degrees latitude, the angle of the noon sun is lowest and the length of daylight is shortest on June 21.
Explanation;
-On June 21 you will note that the Northern Hemisphere is pitched toward the Sun. This means that the Sun's vertical ray is striking the Earth at the Tropic of Cancer (23.5 degrees N).
-Days tend to get longer in the northern hemisphere from December 21 to June 21, and then grow shorter from June 21 to December 21. The June solstice is the summer solstice in the Northern Hemisphere and the winter solstice in the Southern Hemisphere. The date varies between June 20 and June 22, depending on the year, and the local time zone.
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
Answer is B.
Because velocity is vector quantity, so magnitud and direction are needed to define it.
Since velocity means the speed(magnitude) of some object in a given direction, so it’s units are usually measured by meters/ seconds
The guys before me was almost right. But instead of it being vertical it is horizontal.
