In any case, your mass would be<em> 68 kg </em>no matter what
Answer:
Avoid downed power lines and stay away from buildings and bridges from which heavy objects might fall during an aftershock. Stay away until local officials tell you it is safe. A tsunami is a series of waves that may continue for hours. Do not assume that after one wave the danger is over.
In the writing of ionic chemical formulas the value of each ion's charge is crossed over in the crossover rule.
Rules for naming Ionic compounds
- Frist Rule
The cation (element with a negative charge) is written first in the name then the anion(element with a positive charge) is written second in the name.
- Second rule
When the formula unit contains two or more of the same polyatomic ion, that ion is written in parentheses with the subscript written outside the parentheses.
Example: Sodium carbonate is written as Na₂CO₃ not Na₂(CO)₃
- Third rule
If the cation is a metal ion with a fixed charge then the name of the cation will remain the same as the (neutral) element from which it is derived (Example: Na+ will be sodium).
If the cation is a metal ion with a variable charge, the charge on the cation is indicated using a Roman numeral, in parentheses, immediately following the name of the cation (example: Fe³⁺ = iron(III)).
- Fourth rule
If the anion is a monatomic ion, the anion is named by adding the suffix <em>-ide</em> to the root of the element name (example: F = Fluoride).
The oxidation state of each ion is also important, thus in the crossover rule, the value of each ion's charge is crossed over.
Learn more about chemical formulas here:
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Answer:
option (a) 0.61 s
Explanation:
Given;
Time taken by the ball to reach the ground = 0.50 s
Let us first calculate the distance through which the ball falls on the ground
from the Newton's equation of motion, we have
where,
s is the distance
a is the acceleration
t is the time
here it is the case of free fall
thus, a = g = acceleration due to gravity
u = initial speed of the ball = 0
on substituting the values, we get
or
s = 1.225 m
Now,
when the elevator is moving up with speed of 1.0 m/s
the initial speed of the ball = -1.0 m/s (as the elevator is moving in upward direction)
thus , we have
or
or
4.9t^2 - t - 1.225 = 0
or
t = 0.612 s
hence, the correct answer is option (a) 0.61 s
