Physics of shooting in a bike chase

Here’s a fairly common scene in a lot of action movies: 

A hero (usually male) is riding a bike (a fancy one) very fast while being chased by bad people. These goons aren’t just chasing him, but they are also firing bullets at him. Our hero ducks to dodge the bullet and miraculously dodges every bullet fired his way. 

There is a flaw in this picture: 

Even if we assume our hero has superhuman reflexes, it’s still not possible to dodge bullets just by the sound of the...

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Story of an unwritten story

I have a trampoline on which I love to jump with my 3-year-old kid.

One day, I jumped on it for about half an hour. After I was done, I tried to jump on the floor. It was almost impossible. My ankle just won’t fire. I had this idea — If jumping on a trampoline is like jumping on the moon, then jumping on a planet with more gravity than earth’s gravity would be more difficult.

In order to feel how it would be to jump on a planet with more gravity, you can just jump on a trampoline...

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Fake Currency Puzzle

I made this riddle as a teenager when someone gave me a fake note.

Here’s the riddle:

Let’s say you own a small bakery. Someone came to your shop and purchased goods worth 10 bucks. They gave you a fake note of 100 bucks.

You gave them 90 bucks as change. 

Question: How much did you lose?

See answer

Hide answer
100 bucks. The easiest way to think about this is that if those 100 bucks weren’t fake, then you would have made no profit, no loss. So...

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Origin of phrases and thinking from fundamentals

I live in Punjab. Generally speaking, we like the rain. It cools the hot weather, waters our fields - agriculture is a big part of income, and the produce feeds almost all of India.

So I couldn’t figure out the idiom "Saving for a rainy day." It just seemed so wrong and remained that way for many years. I just couldn’t get myself to use the idiom.

The mystery of the idiom finally got resolved when I went to Belfast, UK for Masters in Business studies. 

People just hated the...

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Gravity and the illusion of "Up"

If it wasn’t for earth’s gravity, we would kinda be like the following picture:

In fact, the boy standing at the top would kinda be floating as well. That is assuming we could have any life without gravity. 

No matter where we are on the globe, we have a sense of up and down. That’s because the above image is wrong. The truth looks more like the following image (except the part where everybody holds hands and is happy):

What is up?

"Up" is just away...

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Get payments with Payoneer

If you are in a country that doesn’t support getting payments with PayPal, you can make a Payoneer account to receive payments with us.

We can send payments to US  accounts, and Payoneer gives you a virtual US account. When we deposit money in your virtual US account, Payoneer sends that money to your local bank account.

Here’s how you can receive payments from us from almost any country:

Step 1: Register at

Step 2: Get a virtual US account...

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Get payments via TeacherOn

We have launched a payment option for you to receive payments through us.

Just because you got a student through us, you don’t need to receive payment from that student via us.

Why is it not mandatory to get payments via TeacherOn?

Since most teachers already pay coins to contact students, we feel it is not right to take a commission from earnings as well.

So why did we give this feature?

Many teachers requested this feature to: 

Get payments from...

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Coin Price increase when paying in INR

For the last couple of years, the price for 50 coins was ₹50.
From September 25th, 2019, we are going to link the price of coins to USD. 
This will increase the price of 50 coins to approx ₹70. Also, the price will vary according to the USD-INR rate. 

Why I wrote this post? After I sent the email announcing the price increase, most people just bought coins in bulk. Others mailed us suggesting it’s wrong to increase the price - and we were violating their trust. 


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The price to apply for jobs will now drop faster

The price to contact a student drops gradually to zero if insufficient ( less than 3) teachers contact that student. 

Earlier, the job became free to apply in 48 hours. Now it takes just 36 hours.

Based on the response, we may further reduce it to 24 hours but no promises yet.

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Why is there a wait time to apply to jobs

I have received hundreds of emails from premium members requesting early access to jobs.

We put a lot of time and effort to implement this feature. However, now we are getting emails from non-premium (but paid) members suggesting that the wait is unfair and we are somehow getting greedy.

Why did we do it the way we did?

Giving early access to premium members was obvious and fair. So the decision to give them early access was easy.


All premium members are...

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