A 19 m length of hose is wound around a reel, which is initially at rest. The inertia of the reel is 0.44 kgm2, and its radius is 0.18 m. When the reel is turning, friction at the axle exerts a torque of magnitude of 3.4 Nm on the reel. If the hose is pulled so the tension in it remains constant 29 N, how long does it take to completely unwind the hose from the reel

Explanation:

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Answerthe energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.explanationwe define electric potential as the ratio electric potential energy to the charge,    then the following gives us the potential difference,      the formula  may be on your formula sheet.the change in electric potential energy would be the energy that would needed to move it from point a to point b. solving for that, we get    using q = 8.00  × 10⁻¹⁹ c and  δv = 2.00 v, we get    the energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.

The chemical reactions lab we did is typically called a "copper plating lab,  because the acid solution cleaned the pennies and made the copper look shinier;   the acid solution cleaned the paperclips and made them look like pennies;   &   the copper from the pennies was removed, and then added to the paperclips.