Answer:
Explanation:
Let T be the tension
For linear motion of hoop downwards
mg -T = ma , m is mass of the hoop . a is linear acceleration of CG of hoop .
For rotational motion of hoop
Torque by tension
T x R , R is radius of hoop.
Angular acceleration be α,
Linear acceleration a = α R
So TR = I α
= I a / R
a = TR² / I
Putting this value in earlier relation
mg -T = m TR² / I
mg = T ( 1 + m R² / I )
T = mg / ( 1 + m R² / I )
mg / ( 1 + R² / k² )
Tension is less than mg or weight because denominator of the expression is more than 1.
Positive - Friction allows us to create heat in a desperate situation, like being lost in the woods. If we didn't have friction, we would probably freeze to death.
Negative - Friction can also cause unwanted fires, such as forest fires. If friction didn't exist, we wouldn't have these.
The volume of the water, which was initially 100mL changed to 96mL after refrigeration because the volume of water reduces when cool.
<h3>Why does water change in volume?</h3>
Water is a substance that is known for its unique characteristics that makes it stand out among all other liquids.
One notable feature of water is it's ability to become denser when subjected to cooler temperatures i.e. water is more dense when cold.
As water cools or becomes less warm, it contracts and decreases in volume. When water decreases in volume, it becomes more dense.
Therefore, according to this question, it can be said that the volume of the water, which was initially 100mL changed to 96mL after refrigeration because the volume of water reduces when cool.
Learn more about water volume at:brainly.com/question/17322215
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Answer:
3.176hours
Explanation:
270/85=3.126 hours DISTANCE / SPEED = TIME
