Physics
ρ = m/V — solve for density, mass or volume · 7 curricula
Remaining amount or half-life from decay
Q = mcΔT — solve for heat, mass, specific heat or ΔT · 3 curricula
Solve for pressure, volume, moles or temperature
KE = ½mv² — solve for energy, mass or velocity · 3 curricula
p = mv — solve for momentum, mass or velocity · 3 curricula
F = Gm₁m₂/r² — solve for force, mass or distance · 7 curricula
F = ma — solve for force, mass or acceleration · 7 curricula
V = IR — solve for voltage, current or resistance · 7 curricula
PE = mgh — solve for energy, mass or height · 3 curricula
n₁sinθ₁ = n₂sinθ₂ — solve for index or angle · 3 curricula
Reaction + braking by speed
Solve any of s, u, v, a, t from the equations of motion
v = fλ — solve for speed, frequency or wavelength · 3 curricula
The Leap Second Is Formally Abolished From 2027. A New Definition of the Second Has to Wait
The weights-and-measures conference adopted continuous UTC unchanged, but found no consensus on which atom sho...
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17 Oct
Gas Clouds Near Earth Glow in Gamma Rays, and China's LHAASO Used Them to Count Cosmic Rays
Charged particles from deep space cannot be traced to their sources, so astronomers study the interstellar mat...
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30 Sep
Why Some Decades Have Slightly Longer Days: Gravity Inside Earth
Earth's day drifts by milliseconds over decades. A model in Nature says gravity pulling the inner core into li...
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28 Sep
Thirteen Trapped Ions Simulated Particles Appearing From a Snapped String
A Duke-led team reproduced string breaking, a process from particle physics, on a trapped-ion machine. A class...
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27 Sep
Pompeii's Eruption Date Let Geologists Check Argon Dating, and It Was 0.4% Off
Pliny the Younger's account gave a known age to test against. Eight crystals from Vesuvius also yielded a shar...
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27 Sep
Disorder Can Stabilise a Network. Identical Parts Can Break It.
Variation helps a grid, a swarm or a food web, but only when the individual units have enough behaviour of the...
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20 Sep
Physicists Built a Muonium Beam to Test Whether Gravity Treats All Matter Alike
Muonium fired out of superfluid helium at 2,180 metres per second will let physicists drop a second-generation...
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18 Sep
A Thousand Control Cycles Became One. What That Buys Is Time.
Chalmers researchers compressed control of a quantum encoding into a single Floquet period. The speed matters...
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12 Sep