At the instant the second bulb is connected ...
... the brightness of the <u>first bulb</u> doesn't change
... the brightness of the <u>second bulb</u> changes from dark (no brightness) to equal to the first bulb
The highest value with greatest significant figures is 0.0004200 grams.
Answer: Option A
<u>Explanation:
</u>
Significant numbers are values, often measurements that contribute to the accuracy of the value. We'll start by calculating significant numbers with the first digit without zero. Calculate the number of significant digit from a series of numbers.
These have several rules to be followed for the calculation of number of significant figure at a given value. Following lead with zeros are not significant rules, we have, for option A, number of significant figure number values as 4. And, option D, we have the significant figure number value as 3. While for option B, significant figure all non-zero digits so as 3.
For option C, we have significant figure as 2 as rule is if the digit ends "0" and no decimal point, then all zeros between the position where decimal point is and non-zero numbers are not significant. Thereby, the greatest significant figure value be the option A following the rule of trailing zeros.
Explanation:
It isn't possible to learn an entire language fast. For an examination, memorise some of the easy words. Practice mew minutes speaking French and keep speaking it till you know it.
You will have to use this formula:

Final Velocity (V) = 4m/s
Initial Velocity (Vo) = 8m/s
Acceleration (a) = ? m/s^2
Time (t) = 2 secs
Then:
-> 4 = 8 + a x 2
-> 4 - 8 = 2a
-> -4 = 2a
-> a = -4/2
-> a = -2 m/s^2
Ps: It's value is negative because the she was in retrograde motion.
Answer: Her acceleration is -2 m/s^2.