Answer:
2.16×10⁻⁶ N
Explanation:
Applying,
F = kqq'/r² (coulomb's Law)....................... Equation 1
Where F = electrostatic force, k = coulomb's constant, q = charge on the styrofoam, q' = charge on the grain of salt, r = distance between the charges.
From the question,
Given: q = 0.002 mC = 2.0×10⁻⁶ C, q' = 0.03 nC = 3.0×10⁻¹¹ C, r = 0.5 m
Constant: k = 8.99×10⁹ Nm²/C²
Substitute these values into equation 1
F = (2.0×10⁻⁶)(3.0×10⁻¹¹)(8.99×10⁹)/0.5²
F = 2.16×10⁻⁶ N
Answer:

Explanation:
Given that,
The magnitude of magnetic field, B = 2.21
We need to find the magnitude of the electric field. Let it is E. So,

Put all the values,

So, the magnitude of the electric field is equal to
.
Answer:2.67kgm/s cube
Explanation: density = mass ÷ volume = 400 ÷ 150
Answer:

Explanation:
Average speed is given by
where
is total distance and
is time.
Plugging in given values, we get:
.
Answer:
2.345 would be the most precious because you have more numbers to work with and exact numbers