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1. ### physics questions?

...emission (γ-emission) Q3. An alpha particle which is the same as a helium nucleus (consisting of 2 protons and 2 neutrons). A...

1 Answers · Science & Mathematics · 20/11/2020

2. ### A skydiver is descending with a constant velocity. Make a free-body diagram of all the forces acting on the skydiver. ?

...buoyancy acting upwards.  (This is the force that makes a helium balloon rise for example.) So if I were answering I...

2 Answers · Science & Mathematics · 19/11/2020

3. ### A 633 nm helium -neon laser puts out 6.00 W of power with a beam 6.00 mm in diameter. The beam is pointed directly at a pinhole ?

per photon, E = hc/λ = 6.626e-34kg·m²/s * 3e8m/s / 633e-9m E = 3.14e-19 J power through the hole is P = 6.00J/s * (1.60/6.00)² = 0.427 J/s 0.427J/s / 3.14e-19J/photon = 1.36e18 photons / s If you find this helpful, please select...

1 Answers · Science & Mathematics · 16/11/2020

4. ### how much lighter is a vacuum than hydrogen?

Hydrogen gas at STP has a density 0f 0.08988 g/L = 5.611 lbs / 1000 cubic feet. So 1000 cubic feet of vacuum could life 68 + 5.6 = 73.6 pounds. Problem is, hydrogen gas pushes out on its container, so the balloon can...

1 Answers · Science & Mathematics · 21/11/2020

5. ### chemistry help?

n = PV / RT = (13 mmHg) x (2.6 L) / ((62.36367 L mmHg/K mol) x (30 + 273) K) = 0.001789 mol He (0.001789 mol He) x (4.002602 g He/mol) = 0.00716 g He

1 Answers · Science & Mathematics · 28/10/2020

6. ### Physics question ?

... all of these, you should remember that an alpha particle is basically a helium nucleus, charge +2. It's much more massive than the beta particles...

1 Answers · Science & Mathematics · 21/10/2020

7. ### Physics mass-energy imbalance question!?

Helium /Atomic mass 4.002602 u, and C 12.0107 u He (4.002602) x 3 = 12.007806 g He - C = 12.007806 g - 12.0107 g = -0.002894 g (mass lost) E = mc² = 0.002894 g(1kg/1000g) *299792458)² = 2.60100 × 10^11 J

1 Answers · Science & Mathematics · 10/10/2020

He is 4.002 g/mol 35 m³ = 35000 liters n = PV/RT = (600)(35000) / ( 8.314)(273.16+40) = 8066 mol 8066 mol x 4.002 g/mol = 32280 g or 32.3 kg Ideal gas law PV = nRT n = number of moles R = gas constant = 0.08206 (atm∙L)/(mol...

1 Answers · Science & Mathematics · 09/10/2020

9. ### What is the final pressure of helium and neon gas mixture in this case?

((10.0 mol x 5.00 bar) + (5.00 mol x 20.0 bar)) / (10.0 mol + 5.00 mol) = 10.0 bar

2 Answers · Science & Mathematics · 04/10/2020

10. ### What is the diameter of a 1200g weather balloon at 110,000 ft?

...ft will always vary. However if you approximate those pressures, assume helium is an ideal gas (cause at those pressures and temperatures...

2 Answers · Science & Mathematics · 02/10/2020