An experimenter's diary reads as follows: ''a charged particle is projected in a magnetic feld of `(7.0 veci - 3.0 vecj )X 10^(-3)` T. The acceleraation of the particle is found to be `(square veci +7.0 vec j) X10 ^(-6) ms^(-2)'. The number to left of `veci` in the last expression was not readable. What can this number be?

Explanation

To solve the problem step by step, we will analyze the given information and apply the relevant physics concepts.

### Step 1: Identify the Given Information
We have the following information:
- Magnetic field \( \vec{B} = (7.0 \hat{i} - 3.0 \hat{j}) \times 10^{-3} \, \text{T} \)
- Acceleration \( \vec{a} = (x \hat{i} + 7.0 \hat{j}) \times 10^{-6} \, \text{m/s}^2 \), where \( x \) is the unknown value we need to find.

### Step 2: Understand the Relationship between Force, Magnetic Field, and Acceleration
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