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Questions tagged [physics]

Questions on the mathematics required to solve problems in physics. For questions from the field of mathematical physics use (mathematical-physics) tag instead.

This tag is for questions on the mathematics required to solve problems in physics and should not be confused with those on physics concepts. Pure physics questions should go in the Physics Stack Exchange. For questions in the field of mathematical physics, please use the tag instead.

5951 questions
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Mass of Ocean to Atmosphere

This is a bizarre question, but here goes... If all of the water in the oceans were boiled into steam by the newly forming molten earth, could the atmosphere retain the steam? In other words, how much "space" does the water of the oceans…
David Caldarola
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Finding taking-off Speed? Help

An athlete jumps a horizontal distance of $7.18$m. He was airborne for $2.29$ seconds. The acceleration due to gravity is taken as $9.81$ms$^{-2}$. Assume that air resistance is negligible. Calculate the take-off speed in ms$^{-1}$
David
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Can someone explain why acceleration is not negative in this problem?

Studying for a Physics exam and I'm going back through the homework and redoing the problems. I've come to a problem and am a little confused on the equations. The problem is: With what speed must a ball be thrown vertically from ground level to …
secondubly
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How much is does it take for the stone to reach the bottom?

So a stone is thrown vertically upward with a speed of 10.0 m/s from the edge of a cliff 65.0 m high. So, just making sure I have all my variables right Vinitial: 10 m/s V: 0 m/s g: -9.8 m/s^2 y= 0 m y initial: 70.10 m I got 70.10 m by doing…
Andrea
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Physics: Help me understand this vector problem?

So I'm doing Physics homework - and I already have a rather crappy understanding of vectors, this problem just frustrates me because I have literally 0 idea of what to do with the information it gives me. Could anyone break it down so that I can…
secondubly
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Find the speed required for a boat to "catch" a key dropped from a bridge.

So I'm doing a simple Physics homework problem, and I'm honestly unsure if I'm using the proper formulas for each step. The problem is as follows: A key falls from a bridge that is 47 m above the water. It falls directly into a model boat,…
secondubly
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Calculate how long a ball will be in the air after being thrown

So I'm doing some online homework, and have done this specific problem 3 different times and gotten the same answer, but the answer I get seems to be wrong? The problem is as follows: (a) With what speed must a ball be thrown vertically from ground…
secondubly
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Railway track and Cyclist crossing, Motion Problem.

A railway track runs parallel to a road until a turn brings the road to railway crossing. A cyclist rides along the road everyday at a constant speed 20 km/hr. He normally meets a train that travels in same direction at the crossing. One day he was…
RE60K
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Solving 2 equations (Projectile motion)

The question is from Physics, but all I need is help on solving maths. So basically, i am trying to find out the optimal angle for projectile motion from a certain height and I end up with these two equations: $$0=h + R \tan \theta - R^2 \frac…
aavatar
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Right way to transform $s(t)=1/2g*t^2$ to $v$

My problem is, that I have the following: $$s(t)=\frac {gt^2}{2}$$ and I need to transform it to get $v$. Just can't find the right way to do it.
Timo Güntner
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Applying thin lens formula

Let's say we have an object that in reality has a size A m, know it appears on the image plane with a size A'. We want to know the distance between the optical center (the lens) and the object. What we have is the thin lens formula $$\frac{1}{f} =…
Derk
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Displacement vectors

A rabbit trying to escape a fox runs north for 8.0m, darts northwest for 1.0m, then drops 1.0m down a hole into its burrow. What is the magnitude of the net displacement of the rabbit? So I drew two triangles and tried to solve it using pythagorean…
Lil
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Displacement vectors

You walk $53$ m to the north, then turn $60$ degrees to your right and walk another $45$ m. Determine the direction of your displacement vector. Express your answer as an angle relative to east. So I did pythagorean theorem and got the adjacent…
Lil
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Can someone check my work for this problem? Newton's second law of motion

At $560$ metric tons, the airbus A-$380$ is the world's largest airliner. Whats the upward force on an A-$380$ when the plane is flying (a) at a constant altitude and (b) accelerating upward at $1.1 \: m/s^2$ So I know $f=ma$ So for part a I…
Lil
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Conversion problem

A cereal box says "net weight 340 grams" What's the actual weight (a) in SI units and (b) in ounces? What does net weight mean? Can I just go about this problem by simply converted the gram to SI units and ounces?
Lil
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