contestada

One skier covered the distance of 20 km 20 minutes faster than the other skier. find the speed of both skiers if one of them is travelling 2 km/hour faster than the other one.

Respuesta :

jushmk
Distance covered = 20 km
Let x km/h be the  speed pf first sky. Then, speed of second sky will be (x+2) km/h

Time = distance/speed

Therefore,

20/x - 20/(x+2) = 20 minutes = 1/3 hrs
Solving;
20(x+2) - 20(x)= x(x+2)*1/3
60(x+2) - 60(x) = x^2+2x
60x+120-60x =x^2+2x
120 = x^2+2x
x^2+2x-120 = 0

Then,
x = {-b+/- sqrt (b^2-4ac)}/2a = {-2+/- sqrt(2^2-4*a*-12)}/(2*1) = 10 or -12

Ignoring the negative value, x = 10 km/h

Therefore, the first sky is travelling at 10 km/h while  the  second is travelling at (10+2) 12 km/h

The speed of both skiers will be 10 km/h. Distance is found as the product of speed and time. The given relation is used to solve the problem.

What is the distance?

Distance is a numerical representation of the distance between two objects or locations.

The distance can refer to a physical length or an estimate based on other factors in physics or common use. |AB| is a symbol for the distance between two points A and B.

The given data in the problem is;

Distance travelled = 20 km

Let the first sky's speed be y  km/h. From the given conditions the second sky's speed will then be (y+2) km/h.

The distance is found as;

[tex]\rm distance = speed \times time[/tex]

[tex]\rm Time = \frac{Distance }{Speed}[/tex]

According to the question;

One skier covered the distance of 20 km 20 minutes faster than the other skier;

[tex]\rm T_1-T_2= 20 minute \\\\ \rm T_1-T_2= \frac{1}{3}\ hrs \\\\ \frac{20}{y} -\frac{20}{y+2} = \frac{1}{3}\ hrs \\\\ 20(y+2) - 20(y)= y(y+2)\frac{1}{3} \\\\ 60(y+2) - 60(y) = y^2+2y\\\\ 60y+120-60y =y^2+2y\\\\ 120 = y^2+2y\\\\ y^2+2y-120 = 0[/tex]

Furthur solving the given quadratic equation we will get;

y= 10

y=-12

(- ve) value in terms of velcity is not possible.

y= 10 km/h

Hence the speed of both skiers will be 10 km/h

To learn more about the distance refer to the link;

https://brainly.com/question/26711747

#SPJ3