MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Sanika Phatak Grade: 12
        

A swimmer can swim with velocity v wrt still water in a river flowing with velocity u in the same direction as man. There is a float moving with river. The man overtakes the float and gets a lead of l and then returns back to the float so the time taken in this process is what?


The answer is2l/v Plz explain how??

6 years ago

Answers : (4)

Shivam Bhagat
22 Points
										1.   Relative speed of man=u+v  (downstream direction)

Distance=l
Relative speed of man and float=u+v-u
(same direction)=v
T1=l/t

2. Relative speed of man=v-u(upstream)
Distance =l
Relative speed of man and float=v-u+u
(opposite direction)=v
T2=l/v
Therefor total t is l/v + l/v =2l/v
6 years ago
Thareeq Roshan
31 Points
										

1040_27320_Boat.jpg


First consider the case where the swimmer gains a lead of "l" to the boat.


to find the time required for the swimmer to reach P, we need to know the relative velocity of the swimmer ...


here he is going downstream therefore,velocity of swimmer V(s)=v+u


                                                       velocity of boat V(b)=u


 therefore the relative velocity of the swimmer with respect to the boat ,


                                            V=(v+u) - u


                                              =v


there fore time taken,t(1)=l/v


 


similarly in the upstream the relative velocity of the swimmer is V=(v-u) - (-u)


                                                                                            =v - u + u


                                                                                                                                           =v


there fore the time taken to return the boat t(2)=l/v


 


there fore the total time taken T=t(1)+t(2)=l/v + l/v = 2l/v 


 


pls approve...


 


BEST OF LUCK

6 years ago
iit jee
44 Points
										

hi


relative velocity of man (down stream)=v+u.


speed of boat =u


therefore the velocity of man wrt boat is v+u-u=v


time1=l/v


time2(to return)=l/v


therefore total time is 2l/v


 

6 years ago
Vikas TU
6853 Points
										

downstream ,velocity of swimmer V(s)=v+u


velocity of boat V(b)=u


therefore the relative velocity of the swimmer with respect to the boat , V=(v+u) - u =v


time taken,t(1)=l/v


similarly in the upstream the relative velocity of the swimmer is V=(v-u) - (-u) =v - u + u =v


 then the time taken to return the boat t(2)=l/v 


 the total time taken:


T=t(1)+t(2)=l/v + l/v = 2l/v


All the best!


Smile

6 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete Physics Course - Class 12
  • OFFERED PRICE: Rs. 2,756
  • View Details
  • Complete Physics Course - Class 11
  • OFFERED PRICE: Rs. 2,968
  • View Details

Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details