Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
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Used and loved by over 6 million people
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including olympiad champions, researchers, and professionals.
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, interactive explorations.
Used and loved by over 6 million people
Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.
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Astronauts in microgravity aboard the International Space Station can't use a normal scale to weigh themselves. One way they measure their mass is by riding a large compressed spring.
When the spring is released, a computer compares the motion to how the spring moves without the added mass of the person.
What will happen to the motion of the spring when the astronaut gets on the spring?
by
Blake Farrow
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If we know all 4 side lengths of a quadrilateral, can we determine the area of the quadrilateral?
Note: Heron's formula allows one to determine the area of a triangle given the 3 side lengths.
by
Pi Han Goh
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True or False?
If you add a positive number to its reciprocal, then the result is always greater than or equal to 2.
\[x + \frac{1}{x} \ge 2\]
Bonus: If true, give the relevant proof; if false, explain why.
by
Ram Mohith
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A clock with no numbers fell to the ground.
What time is it?
by
上和 江
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The numbers in the circles follow the pattern shown below.
In which horizontal row of circles does the number \(2018\) first appear?
by
Hana Wehbi
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