Answer:
I(7) = 22.96 W/m²
Step-by-step explanation:
Let intensity of light, be I(d) where d is distance. There must be a proportionality factor K such as
I(d) = K /d²
Now for d = 5 m I(d) = K* 1/d²
then 45 * 25 = K
K = 1125
To find the intensity when the distance from the light bulb is 7 m away
I(7) = K / 49
I(7) = 1125/49 W/m²
15 units
d = 14.866
d = 15
50 is more than 27
27 comes before 50
+= 34
The equation of a circle in standard form is
+=
where (a , b) are the coordinates of the centre and r is the radius
The centre is at the midpoint of the endpoints and the radius is the distance from the centre to either of the 2 endpoints
Using the midpoint formula
midpoint = [(x+, (+
where (,=(3,8) and (,=(-7,2)
centre = ((3-7),(8+2)) = (-2,5)
Calculate r using the distance formula
r = √(-)²+(-)²)
= √((3+2)²+(8-5)²) = √(25+9) = √34 ⇒ r² =(√34)² = 34
equation of circle is : (x+2)²+(y-5)² = 34
2 hours at 15mph
4 hours at 4mph