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:
The maximum height of the ball is 2 m.
Explanation:
Given that,
Mass of ball = 50 g
Height = 1.0 m
Angle = 30°
The equation is

We need to calculate the velocity
Using conservation of energy

Here, ball at rest so initial kinetic energy is zero and at the bottom the potential energy is zero

Put the value into the formula

Put the value into the formula




We need to calculate the maximum height of the ball
Using again conservation of energy

Here, h = y highest point
Put the value into the formula



Put the value of y in the given equation




Hence, The maximum height of the ball is 2 m.
Answer:
Yes
Explanation:
An increased speed will result in an increased amount of energy, so when it crashes some of that energy will bounce back and crumple the car.
B. Purchase a small plastic container and mark 1-ounce increments on the outside to determine volume. Pour 5 ounces of water into the container, and place in the freezer for 8 hours. Compare the frozen or ending volume with the liquid or beginning volume.
<h3>How much water expands when frozen?</h3>
Ice is less denser than the liquid form. Water is the only known non-metallic substance that expands when it freezes because it is the unique property of water. Water density decreases and it expands approximately about 9% by volume. For calculating the expansion of water, plastic container is the best option. We know that water expands when the water freezes because it is a unique property of water which allows the survival of aquatic organisms.
So we can conclude that option B is the right answer.
Learn more about water here: brainly.com/question/1313076
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Hi , the answer is D , battery.