1 kilometers =1000 meters
0.86km=0.86*1000=860m
John swam 860 meters each day.
1 week = 7 days
3weeks=3*7=21
21*860=18060 m
Therefore he swam 18060 meters in those three weeks.
E = 1/2 m v^2
E = 1/2 (0.145) (40)^2
E = 0.0725 x 1600
E = 116 kg m^2/s^2
1 joule = 1 kg m^2/s^2
so here E in joules is 116 joules
so E = 116 joules
Answer:
Distance between the surface and source of light will be increased by 6 meters.
Step-by-step explanation:
The illuminance of a surface varies inversely with the square of ts distance from the light source.
Let illuminance of the surface = x lumens per square meter
and distance from a light source = y meter.
Now x ∝ 
Or
[k = proportionality constant]
Now we will find the value of k.
k = xy²
k = 120×(6)²
k = 4320
We have to calculate the distance of the source if illuminance of the surface is 30 lumens per square meter.

y² = 
y² = 144
y = √144 = 12 meters
So the source of the light will be shifted away from the surface = 12 - 6 = 6 meters.
Answer:
answer is 5.4 hours (rounded)
Step-by-step explanation:
8.4 divided by 40 is 4.76
15 divided by 40 is 2.66
add those two up and it'll be 7.42
7.42 divided by 40 is 5.3908
In the fourth step, he didn’t put the “negative” sign for 4.