# Help again

A man is running up an incline planr maaking an angle $\theta$ with horizontal with a speed u .Rain drops falling at an angle $\alpha$ with the vertical appear to the man as if they are falling at an angle of $45^o$ with the horizontal. The speed of rain drops is

Note by Kyle Finch
5 years, 5 months ago

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

• Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
• Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
• Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
• Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold
- bulleted- list
• bulleted
• list
1. numbered2. list
1. numbered
2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in $$ ... $$ or $ ... $ to ensure proper formatting.
2 \times 3 $2 \times 3$
2^{34} $2^{34}$
a_{i-1} $a_{i-1}$
\frac{2}{3} $\frac{2}{3}$
\sqrt{2} $\sqrt{2}$
\sum_{i=1}^3 $\sum_{i=1}^3$
\sin \theta $\sin \theta$
\boxed{123} $\boxed{123}$

## Comments

Sort by:

Top Newest

Take relative velocity along x and y axes and equate magnitude

- 5 years, 5 months ago

Log in to reply

While talking about the rain, you took its direction in the south west direction. What prompted you to do that?? Why didn't you take it in the south-east direction?? In that case the x-component of relative velocity will be

ucos(theta)-vsin(alpha) and not ucos(theta)+vsin(alpha) as in this case...

- 5 years, 5 months ago

Log in to reply

Both are equivalent. Just interchange $\alpha$ in my equation with $-\alpha$ to get to the result that you have mentioned. This disparity arises since I am measuring the angle in the clockwise direction, while you are measuring it in the anticlockwise direction.

- 5 years, 5 months ago

Log in to reply

Yea, but the final expressions for the velocity are completely different...Then how are the results equivalent??

- 5 years, 5 months ago

Log in to reply

Yes i solved it . Any way thanx for helping .

- 5 years, 5 months ago

Log in to reply

$v=u \sin {(\pi/4 -\theta)} \csc {(\pi/4 -\alpha)}$

- 5 years, 5 months ago

Log in to reply

Shouldn't be there plus sign in sin part

- 5 years, 5 months ago

Log in to reply

Can u explain in brief

- 5 years, 5 months ago

Log in to reply

- 5 years, 5 months ago

Log in to reply

×

Problem Loading...

Note Loading...

Set Loading...