Answer:
29 counts per minute (29 cpm)
Explanation:
The half-life of a radioactive isotope is the time needed for the activity of the sample to halve.The half-life of Francium-223 is exactly 22 minutes: this means that its activity after 22 minutes becomes exactly half of its initial value. Since the initial activity of this sample of francium-223 was 58 cpm, the activity after 22 minutes will be

Dew point is the temperature at which the water vapor in the air condenses , then evaporates. The barometric or air pressure is independent from the dew point.
Average speed = (total distance covered) / (time to cover the distance)
Ian's total distance covered = (2km + 0.5km + 2.5km) = 5 km.
His time to cover the distance = 3 hours.
Average speed = (5 km) / (3 hrs)
Average speed = (5/3) (km/hr)
<em>Average speed = 1.67 km/hr</em>
Answer: 1.39 s
Explanation:
We can solve this problem with the following equations:
(1)
(2)
Where:
is the length the steel wire streches (taking into account 1mm=0.001 m)
is the length of the steel wire before being streched
is the force due gravity (the weight) acting on the pendulum with mass 
is the transversal area of the wire
is the Young modulus for steel
is the period of the pendulum
is the acceleration due gravity
Knowing this, let's begin by finding
:
(3)
Where
is the diameter of the wire
(4)
(5)
Knowing this area we can isolate
from (1):
(6)
And substitute
in (2):
(7)
(8)
Finally:
