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 pressure of the air molecules inside the pen cap increases and the volume occupied by the air decreases such that the combined volume occupied by the pen cap and the air volume reduces while the combined mass of the pen cap and the air molecules remain the same
Given that density = The mass/Volume, we have that the density varies inversely as the volume, and as the volume reduces, the density increases
Upon squeezing, therefore, as the new combined density of the pen cap and the air molecules rises to more than the density of the water in the bottle, then, the pen cap air molecule is relatively more denser than the water, which will result in the pen cap sinking to the bottom of the bottle
Explanation:

You just do the calculations.
Answer:
you have to substitute the volume of the ballonn with no ruler
Answer:
0.73 m/s
Explanation:
From Newton second law of motion,
I = m(v-u)...................... Equation 1
Where I = Impulse, m = mass of the person, v = final velocity, u = Initial velocity.
make v the subject of the equation
v =(I/m)+u................. Equation 2
Note: u = 0 m/s as the person is falling from an height.
Given: I = 55 Ns, m = 75 kg, u = 0 m/s
Substitute into equation 2
v = 55/75
v = 0.73 m/s