The number of hours required : 37.2 hours
<h3>Further explanation</h3>
Given
⁴²K (potassium -42)
Required
The number of hours
Solution
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually, radioactive elements have an unstable atomic nucleus.
Based on Table N(attached), the half-life for ⁴²K is 12.4 hours, which means half of a sample of ⁴²K will decay in 12.4 hours
For three half-life periods :

Answer:
Moment=Force x Pivot
Explanation:
A moment is the turning effect of a force. Moments act about a point in a clockwise or anticlockwise direction.
Law of moments:
When an object is balanced (in equilibrium) the sum of the clockwise moments is equal to the sum of the anticlockwise moments.
How to calculate moments:
Moment=Force x Pivot
Explanation:
what do you mean by "bad"
Distance traveled by the race horse=6 furlongs
Converting the distance from furlongs to rods: 40 rods =1 furlong

Converting the distance from rods to yards, feet and miles: 5.5 yards = 1 rod, 3foot =1 yard, 1 mile = 5280 feet.

The given speed of race horse = 40.7mi/hr
Calculating the time required:

Therefore, 66.34 s is required for a race horse to run six furlongs at 40.7 miles per hour.