You are on a boat in a fog and know there are cliffs ahead of you somewhere, but you cannot see them. you use your fog horn to s
1 answer:
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Answer:
The volume of the larger cube is 5.08 g/cm³.
Explanation:
Given that,
Mass of smaller cube = 20 g
Density of smaller cube
Dylan has two cubes of iron.
The larger cube has twice the mass of the smaller cube.
Density is same for both cubes because both cubes are same material.
The density is equal to the mass divided by the volume.
Where, V = volume
m = mass
We need to calculate the volume of smaller mass
The volume of smaller mass
Now, We need to calculate the volume of large cube
Hence, The volume of the larger cube is 5.08 g/cm³.
Answer:
The rotational kinetic energy takes 0.430 seconds to become half its initial value.
Explanation:
By the Principle of Energy Conservation and the Work-Energy Theorem we know that flywheel slow down due to the action of non-conservative forces (i.e. friction), the energy losses are equal to the change in the rotational kinetic energy. That is:
(1)
Where:
- Energy losses, measured in joules.
,
- Initial and final rotational kinetic energies, measured in joules.
By definition of rotational kinetic energy, we expand the equation above:
(2)
Where:
- Moment of inertia of the flywheel, measured in kilograms per square meter.
,
- Initial and final angular speed, measured in radians per second.
If we know that ,
and
, then the initial angular speed is:
(3)
(4)
Under the assumption that flywheel is decelerating uniformly, we get that the time taken for the flywheel to slowdown is:
(5)
If we know that ,
and
, then the time needed is:
The rotational kinetic energy takes 0.430 seconds to become half its initial value.