Answer:
Explanation:
To solve this problem we need to apply the concept related to Angular Acceleration. We can find it through the equation
Where for definition,
The number of revolution 
was given by 20 times, then
We know as well that the salad rotates 6 more times, therefore in angle measurements that is
The cook at the end stop to spin, then using our first equation,
re-arrange to solve
,
We can know find the required time,
Re-arrange to find t, and considering that 
Therefore take for the salad spinner to come to rest is 3 seconds with acceleration of
It will take 267 milliseconds for a sample of radon-218 to decay from 99 grams to 0. 50 grams.
We know that half life of a first order reaction is given by: 
where k = rate of reaction
Given half life = 35 milliseconds
So from this we get k = 0.0198
Now we know that rate of first order reaction is given by: 
where t= time
R'= initial amount = 99 g
R= final amount= 0.50 g
k= rate of reaction = 0.0198
Putting values of these in above equation we get t=267 milliseconds.
i.e. It will take 267 milliseconds for a sample of radon-218 to decay from 99 grams to 0. 50 grams.
To know more about radioactivity visit:
brainly.com/question/20039004
#SPJ4
The first step of the scientific method is to MAKE OBSERVATIONS
We are given with:
Sensitivity: 100uJ/cm2
Diameter: 10mm
Background Optical Power: 8uW
Source Optical Power: 50uW
Required: exposure time
Solution:
Exposure time = sensitivity x area / (background power - source power)
= 100uJ/cm2 (π/4) (1 cm)² / (80 uW - 50 uW)
= 2.62 s
The exposure time is 2.62 seconds.
