Maths fractions help Question 1-4 thanks
1 answer:
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The formula for circumference is 2
r, where r is equal to radius.
It states to use 3.142 for pi
It also provides you with the diameter, not the radius, so you have to divide it by two to get 4.5
2*3.142*4.5= approximately 28.278 or 28.3
It states to use 3.142 for pi
It also provides you with the diameter, not the radius, so you have to divide it by two to get 4.5
2*3.142*4.5= approximately 28.278 or 28.3
Answer:
(A) 30772cm^2/s
(B) 153860cm^2/s
(C) 184632 cm^2/s
Step-by-step explanation:
We are given
speed of the ripple = 70cm/s
this speed is increasing the radius which means speed = radius /time
radius = speed*time
r= 70t
Now we know the area of the circle
A = π
this area will be increasing as ripples in water will spread out
upon differentiating
dA/dt = 2πr *
dA/dt = 2π*70t*70 ( r= 70t , dr/dt = speed = 70)
dA/dt = 9800π*t
(A) after 1 second
dA/dt = 9800π*1=9800π = 30772cm^2/s
(B) after 5 seconds
dA/dt = 9800π*5 = 153860cm^2/s
(C) after 6 seconds
dA/dt = 9800π*6 = 184632 cm^2/s