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What type of radioactive decay reduces the mass number of a nucleus? Explain how it works.

Alpha radiation reduces the mass number of an atom by 4. When an atom's nucleus is unstably large, it emits an alpha particle which consists of two neutrons and two protons. This is called alpha decay. Since...
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Answered by Francis B. • Physics tutor
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If fusing hydrogen nuclei together puts them into a lower energy state, and matter always wants to be in a lower energy state, then why hasn't all the hydrogen in the universe already done this?

We first need to look at why fusion of hydrogen nuclei results in a lower energy state. On the face of it, hydrogen nuclei are just protons, which all carry an equal positive electric charge. This means they...
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Answered by Callum C. • Physics tutor
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A box is at rest on a slope with an angle ϴ. Find an expression for the static friction coefficient, μ, of the box.

Begin by drawing a diagram with all the vectors that act on the box. This should include the normal vector (N), the weight of the box (G), and the static friction force (F s ). Write down the equation for th...
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Answered by Oliver L. • Physics tutor
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Please describe the change in velocity of someone falling from a plane before they open their parachute

At first, when the parachutist is at 0ms-1 velocity (about to fall) there is only Weight acting downwards on the person, so the resultant force is down. F=ma, therefore the parachutist accelerates downwards....
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Answered by Pearl E. • Physics tutor
3501 Views

If a motor uses 500J to raise a box of 25N, how high has the box been lifted?

Work done = Force x distance the applied force has moved, hence 500 = 25d where d = unknown distance. Therefore the distance moved is 500/25 = 20m
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