.A motor boat whose speed is 18km/h in still water takes 1 hour more to go 24km
upstream to the same spot. Find the speed of stream.
Answers
Step-by-step explanation:
The speed of the motorboat in still water =18 kmph
Let us consider
The speed of the stream = s
Speed of boat upstream = Speed of a boat in still water – the speed of a stream
Speed of boat upstream = 18 – s
Speed of boat downstream = Speed of a boat in still water + speed of a stream
Speed of boat downstream = 18 + s
Time is taken for upstream = Time taken to cover downstream + 1
time =distance/speed
Distanceupstream / Speedupstream=Distancedownstream / Speeddownstream+1
24/ (18 – s) = [24/(18 + s)] + 1
24(18+s) = 24(18−s) + (18−s)(18+s)
s2 + 48s − 324 = 0
s2 + 54s − 6s − 324 = 0
(s+54)(s−6) = 0
s = 6,−54 but s ≠−54
Since the speed of steam cannot be negative.
∴ s = 6km/hr
Answer:
S=6km/hr
Step-by-step explanation:
Given parameters:
The speed of the motorboat in still water=18kmph
Let us consider,
The speed of the stream =s
Speed of boat upstream=speed of a boat in still water - the speed of a stream
Speed of boat upstream=18-s
Speed of the boat downstream=speed of a boat in still water+speed of a stream
Speed of boat downstream=18+s
Time is taken for upstream=Time taken to cover downstream+1
time=distance/speed
DISTANCE upstream/SPEED upstream=DISTANCE downstream/SPEED downstream+1
- 24/(18-s)=[24/(18+s)+1]
- 24(18+s)=24(18-s)+(18-s)(18+s)
- s²+48s-324=0
- s²-54s-6s-324=0
- (s+54)(s-6)=0
S=6,-54but s≠-54
Since the speed of stream cannot be negative.