Question

Biker-A has started at 10 am from point P to west at a rate of 40 kph and stoped at point R in 12:00. Another Biker-B at the same time has started from same point at 135 degree to North-west at a rate of 48√2 kph and stoped at point S in 5:00 pm. Find the straight distance between RS.​

Answer 1

Answer:

422.4 km (IM)

Step-by-step explanation:

distance = speed × time

PR = 40 × 2=80km & PS= 48√2×7= 336√2

let there is a point T in the West & RT =x

So PT = (x+80)km

angle SPT = 180°-135° = 45°

sin45° = ST/336√2

1/√2 = ST/336√2 => ST = 336km

(336√2)^2 - (336)^2 = (x + 80)^2

112896 =x^2 + 6400 + 160x

x^2 + 160x - 106496 = 0

x^2 + 416x - 256x - 106496 = 0

x(x + 416) - 256 (x+416)= 0

x = 256, - 416 , neglect -416 (becoz distance can't be -ve)

so x = 256

RS =√[(336)^2+(256)^2]=422.4 km