i m not able to solve this problem so can someone help me please

Q)A pendulum of length 2 m left at A When it reaches B,it loses 10% of its total energy due to air resistance. The velocity at B is:

A)6 m/s

B)1 m/s

C)2 m/s

D)8 m/s

please help me

Thnx in advance

please reply fast

It is quite a vague question, however...

 

Use the clues given in the question. For instance, it's asking for 'total energy', so potential energy and something else.

 

(Maybe obvious) Hint: The balancing term needs to include velocity.

Edited February 7, 201411 yr by Royston

It is quite a vague question, however...

 

Use the clues given in the question. For instance, it's asking for 'total energy', so potential energy and something else.

 

(Maybe obvious) Hint: The balancing term needs to include velocity.

potential energy and?????????

You need to know where A and B are

You need to know where A and B are

please tell me how to upload pic so i can show you the question

Press More Reply Options, then you can attach files..

Press More Reply Options, then you can attach files..

ok thnx

please see this

now can you help me please

What is angle between A and B picture?

What is angle between A and B picture?

i think its 90 degree

so now ??

What is g ?

 

Again, what equations do you think would answer the question.

 

How can you manipulate those equations to arrive at an answer ?

 

I don't think you need to worry about angles....and I don't think the question assumes you're on the moon .

g is 10

What's the relation between potential energy and kinetic energy when you have no losses to things like air resistance?

What's the relation between potential energy and kinetic energy when you have no losses to things like air resistance?

so then it i potential energy=mgh kinetic energy=1/2 mgh

The PE at the top is the same as KE at the bottom (the sum is constant at any point)

 

So you can solve for the energy and then reduce it by 10% and solve for v

The PE at the top is the same as KE at the bottom (the sum is constant at any point)

 

So you can solve for the energy and then reduce it by 10% and solve for v

I didnt understood please simplify it

someone please help in solving this problem and how?

!

Moderator Note

Members should be aware that the OP Jay Sharma has been banned as a sockpuppet of Rajnish Kaushik.

same question isthere in book excel with physics

please help me by providing since its very very urgent as well as importent for me i request you to do so

please help quickly