1 mile = 5,280 feet
Car + space = 13.5 + 3 = 16.5 feet
5,280 / 16.5 = 320
Answer: 320 cars
Answer:
It will take 7 years ( approx )
Step-by-step explanation:
Given equation that shows the amount of the substance after t years,

Where,
= Initial amount of the substance,
If the half life of the substance is 19 years,
Then if t = 19, amount of the substance =
,
i.e.



Taking ln both sides,



Now, if the substance to decay to 78% of its original amount,
Then 


Again taking ln both sides,



Hence, approximately the substance would be 78% of its initial value after 7 years.
Answer:
central angle=18
arc length=2.5 π feet
area of a sector=31.25π square feet
Step-by-step explanation:
Given
wheel radius=25 feet
attached cars=20
Space between cars along the circumference of wheel= 360/20
=18
Finding arc length:
arc length= radius x angle(in radians)
angle in radian = 18 x π/180 = 0.1π radians
arc length = 25 x 0.1π
=2.5π feet
Area of the circle = πr^2
Area of the circle = π(25)^2
Area of the circle = 625π square feet.
As the ratio of the central angle to the full circle angle is proportional to the area of the sector to the complete circle:
central angle/360=area of sector/area of circle
Area of sector= area of circle x 18/360
= 625π(1/20)
=31.25π !