<span>Dawn was at 6 am.
Variables
a = distance from a to passing point
b = distance from b to passing point
c = speed of hiker 1
d = speed of hiker 2
x = number of hours prior to noon when dawn is
The first hiker travels for x hours to cover distance a, and the 2nd hiker then takes 9 hours to cover that same distance. This can be expressed as
a = cx = 9d
cx = 9d
x = 9d/c
The second hiker travels for x hours to cover distance b, and the 1st hiker then takes 4 hours to cover than same distance. Expressed as
b = dx = 4c
dx = 4c
x = 4c/d
We now have two expressions for x, set them equal to each other.
9d/c = 4c/d
Multiply both sides by d
9d^2/c = 4c
Divide both sides by c
9d^2/c^2 = 4
Interesting... Both sides are exact squares. Take the square root of both sides
3d/c = 2
d/c = 2/3
We now know the ratio of the speeds of the two hikers. Let's see what X is now.
x = 9d/c = 9*2/3 = 18/3 = 6
x = 4c/d = 4*3/2 = 12/2 = 6
Both expressions for x, claim x to be 6 hours. And 6 hours prior to noon is 6am.
We don't know the actual speeds of the two hikers, nor how far they actually walked. But we do know their relative speeds. And that's enough to figure out when dawn was.</span>
Answer:
Force= Mass×Accelaraion
F=m×a
But as The unit of accelaration is given miles per hour and the SI is meters per second sqaure we have to convert 10mph to m/s²
Thus, we have 10mph = 4.47 meters per second square. (i converted using scientific calculator)
So now we have,
2000N= m×4.47m/s²
= 2000/4.47m/s²=m
= 447.42
Thus the mass of the object is 447.42 (i am not sure of units)
P of selecting point on the shaded region = shaded area/whole area
<span>P( selecting point on the shaded ) = ( the four shaded circles ) / the whole square </span>
<span>P of selecting point on the shaded = ( 4 * ( π * r^2 ) )/ x^2 </span>
<span>P of selecting point on the shaded = ( 4 * ( π * (x/4)^2 ) )/ x^2 </span>
<span>P of selecting point on the shaded = ( 4 * ( π * x^2/16 ) )/ x^2 </span>
<span>P of selecting point on the shaded = ( π * x^2/4 )/ x^2 </span>
<span>P of selecting point on the shaded = x^2( π/4 )/ x^2 </span>
<span>P( selecting point on the shaded ) = π/4 ≈ 0.7854 ≈ 79%
=80%
D is right option hope this helps</span>
