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3 years ago

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A marathon runner completes a 42.188–km course in 2 h, 36 min, and 12 s. there is an uncertainty of 23 m in the distance travele

d and an uncertainty of 3 s in the elapsed time. calculate the percent uncertainty in the distance.

1 answer:

timurjin [86]3 years ago

4 0

The percentage uncertainty in the distance is <u>0.054%</u>.

Uncertainty in a measurement measures the deviation of the measured values from the true value.

The distance d can be expressed in the form <em>d+/-Δd, </em>where <em>Δd i</em>s the absolute uncertainty in the measurement of distance.

The percentage uncertainty is given by,

$Percentage uncertainty=\frac{\Delta d}{d} *100$

The uncertainty in the measurement of distance is 23 m. Express the uncertainty in km.

$\Delta d =\frac{23 m}{1000 m/km} =0.023 km$

Calculate the percentage uncertainty in the distance.

$\frac{\Delta d}{d} *100 =\frac{0.023 km}{42.188 km} *100=0.054 %$

Thus, the percentage uncertainty in the measurement of distance is <u>0.054%</u>

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A) The work done by the electric field is zero

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Explanation:

A)

The electric field applies a force on the charged particle: the direction of the force is the same as that of the electric field (for a positive charge).

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B)

In this case, the charge move upward (same direction as the electric field), so

$\theta=0^{\circ}$

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$cos 0^{\circ}=1$

Therefore, the work done by the electric force is

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$F=(32.0\cdot 10^{-9})(4.30\cdot 10^4)=1.38\cdot 10^{-3} N$

The displacement of the particle is

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C)

In this case, the angle between the direction of the field (upward) and the displacement (45.0° downward from the horizontal) is

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While the displacement of the charge is

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Answer:

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To find the spring's displacement;

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