Physics, asked by anuska8, 1 year ago

A motorboat covers the distance between two spots on the river in t1=8h and t2=12h downstream and upstream respectively.What is the time required for the boat to cover this distance in still water?​

Answers

Answered by Anonymous
67

Answer:

T1 = 8 h

T2 = 12 h

Let time requited in still water be t h.

Let Speed of boat be v1 and speed of stream be v2.

For downstream, d = ( v1 + v2) T1

For upstream, d = ( v1 - v2) T2

For still water, d = v1. t

Solve all three equations,

t = 2 T1 T2 / ( T1 + T2)

t = 2 * 8 * 12 / ( 8 + 12 )

t = 192/ 20 = 9.6 h

t = 9.6 h


Anonymous: Thnx to u too.
Answered by raj4913
11

Answer:for downstream take t1 = 8hourand for upstream t2 be 12 hour respectivelyand distance between points be l also take velocity of boat as v and of water v1

Then for downstream

t1 =l/v+v1. (1)

,for upstreamt2=l/v-v1. (2)

Time reqire by boat in still water= t0=d/v. ( 3)

Now t1=l/v/l+v1/l, t2=l/v-v1

1/t1=v/l+v1/l,1/t2=v/l-v1/l

Adding both

1/t1+1/t2=2v/l

V/l=1/2(1/t1+1/t2)

L/v=2/(1/t1+1/t2)

t0=2/(1/t1+1/t2)

Explanation:put the values of t1 qnd t2

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