Measuring which physical property is most likely to produce the most precise results when trying to identify a substance? luster
2 answers:
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Answer:
Explanation:
Given that,
A point charge is placed between two charges
Q1 = 4 μC
Q2 = -1 μC
Distance between the two charges is 1m
We want to find the point when the electric field will be zero.
Electric field can be calculated using
E = kQ/r²
Let the point charge be at a distance x from the first charge Q1, then, it will be at 1 -x from the second charge.
Then, the magnitude of the electric at point x is zero.
E = kQ1 / r² + kQ2 / r²
0 = kQ1 / x² - kQ2 / (1-x)²
kQ1 / x² = kQ2 / (1-x)²
Divide through by k
Q1 / x² = Q2 / (1-x)²
4μ / x² = 1μ / (1 - x)²
Divide through by μ
4 / x² = 1 / (1-x)²
Cross multiply
4(1-x)² = x²
4(1-2x+x²) = x²
4 - 8x + 4x² = x²
4x² - 8x + 4 - x² = 0
3x² - 8x + 4 = 0
Check attachment for solution of quadratic equation
We found that,
x = 2m or x = ⅔m
So, the electric field will be zero if placed ⅔m from point charge A, OR ⅓m from point charge B.
Answer : The correct option is, (a) No. Potatoes will be warmer.
Explanation :
Formula used :
where,
Q = heat taken
m = mass of substance
c = specific heat of substance = ?
= change in temperature
As we are given that the potatoes have a specific heat of and raisins have a specific heat of
. That means higher the value of specific heat the more heat taken by the substance (more warmer will be the substance). So, the potatoes will be more warmer as compared to raisins.
Hence, the correct option is, (a) No. Potatoes will be warmer.