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1. ### A discus thrower applies a force F= (at^2)i +(B + yt)j to a discus with a mass of 2.00 kg; where a = 30.0 N/s^2; B= 40.0 N; and Y = 5.0 N/s:?

Given F= (at^2) i + (B + yt) j  As ∆v/∆t = a = F/m =>dv/dt = 1/2 x {(at^2) i + (B + yt) j} =>dv = 1/2 x {ai...

2 Answers · Science & Mathematics · 18/04/2020

2. ### In vectors a and b find m and n..?

...;a> and <b> are non-parallel, then j<a> + k<b> = 0, if j = k = 0 If j = (m+n+1) and k = -(3n+2), then m+n+1 = 0 3n + 2 = 0 → n = -2/3 m - 2/3 + 1 = 0 m...

2 Answers · Science & Mathematics · 06/09/2019

3. ### Mary weighs 549 N and she walks down a flight of stairs to a level 3.2 m below her starting point. What is the change in Mary’s potential...?

Fd is work done (undone). (549)(3.2).= 1756.8 J It's a negative because potential is lost, so, -1756.8 J.  They probably want...

3 Answers · Science & Mathematics · 13/12/2019

4. ### Physics: Springs: A block of mass 1.4 kg is attached to a horizontal spring that has a force constant 1100 N/m as shown in the figure...?

...½ * 1100N/m * (0.020m)² = 0.22 J At lesser compression, that initial energy has...*1100*0.0040² - 4.2*(0.020 - 0.0040) = 0.144 J and so it seems to me that we have in fact...

1 Answers · Science & Mathematics · 18/10/2019

5. ### What is the wavelength of a photon that will excite an electron from n=3 to n=5 in a hydrogen atom?

change in energy = R(1/3² - 1/5²) = 1.55e-19 J and change in energy = hv / λ so λ = hv / change in energy = 6.626e−34J·s * 2.998e8m/s / 1.55e-19J λ = 1.282e-6 m = 1.282 µm = 1282 nm

2 Answers · Science & Mathematics · 14/06/2019

6. ### A mass-spring system oscillates with an amplitude of 5.80 cm. If the spring constant is 275 N/m and the mass is 582 g,?

1) E = 1/2 k A^2 E = 0.5 * 275 * 0.058^2 = 0.46 J 2) v = w A = sqrt(k/m) A v = sqrt(275/0.582) * 0.058 = 1.26 m/s 3) a = w^2 A = (k/m) A a = (275/0.582) * 0.058 = 27.41 m/s^2

2 Answers · Science & Mathematics · 08/08/2019

7. ### What is the final level that the electron jumps to?

...13.6eV * 1.6e-19J/eV = 2.176e-18 J so 9.17063e-20 J = 2.176e-18J * (1/n² - 1/7²) means that 1/n² = 0.0626 1/n = 0.25 n = 4 Hope this helps!

1 Answers · Science & Mathematics · 27/04/2020

8. ### Find the tangential and normal components of the acceleration vector. (r)= (t^2 +1)I +t^3 j, t>=0?

...t)| / |v(t)| where x represents the cross product and we already know |v(t)| a_n = |(2t i^ + 3t² j^) x (2 i^ + 6t j^)| / √[t²(4 + 9t²)] a_n = |(2t*6t - 3t²*2...

3 Answers · Science & Mathematics · 11/11/2019

9. ### What is the final level that the electron jumps to?

...-19J/eV * (1/n² - 1/7²) 2.13426E-18 J = 2.176E-18J * (1/n² - 1/7²) 0.981 = 1/n² - 1/49 1/n² = 0.981 + 1/49 = 1.00 n = 1 first level

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

10. ### For what values of n, such that 0<n≤100, can the unit fraction 1/n be expressed as a terminating decimal?

... 2 and/or 5 as factors, then it will create a terminating decimal. That's because 2...0.1 1/16 = 0.0625 1/20 = 0.05 etc. Answer: n = 2^i 5^j where i and j are non-negative integers...

2 Answers · Science & Mathematics · 21/03/2020