# Search results

1. ### Satellite orbiting Earth

Question: A 460kg satellite is launched into a circular orbit and attains an orbital altitude of 850km above Earth's surface. Calculate the: e) additional energy and speed required for the satellite to escape. Attempt: I found Ek to be 1.27*10^10 J Thus, the total energy is...
2. ### Negative maximum kinetic energy in Millikan's data?

What am I finding to be confusing.. The graphs of Millikan's data were straight lines with equal slopes. The graph was plotted maimum kinetic energy (eV) versus the frequency of the wave. This was the graph that produced the linear relationship from the photoelectric effect. What does it mean...
3. ### Fletcher's trolley apparatus - maximum value of coefficient

a increases, but will become negative.. a is proportional to μ ....
4. ### Fletcher's trolley apparatus - maximum value of coefficient

That will give me the following: a = [\frac{(mass2)(g) - μ(mass1)(g)}{(mass1 + mass2)}] But then I have a, which I have nothing to sub in for.
5. ### Fletcher's trolley apparatus - maximum value of coefficient

Homework Statement A Fletcher's trolley apparatus is set up with a block of wood of mass 4.0kg and a suspended mass of 2.0kg. The Attempt at a Solution a) Calculate the acceleration of the sys. and the tension in the string when the mass is released. m1 FnetX = [T - Ff = m1(a)] FnetY...
6. ### Quick question about inertial frames of reference

Homework Statement If you are on the merry-go-round going in a circle at constant speed, are you looking at the world in an inertial, or non-inertial frame of reference? How do we tell whether from one's viewpoint, they are looking at something from an interial or non-inertial frame of reference?
7. ### Guy pushing girl on a swing models h.displacement with function

1,2,3. Homework Statement , and work done. After Lee gives his little sister Kara a big push on a swing, her horizontal position as a function of time is given by the equation x(t) = 3cost(t)*e^{-0.05t} , where x(t) is her horizontal displacement, in metres, from the lowest point of her swing...
8. ### Sun radiating energy at a rate

Homework Statement The Sun radiates away energy at the rate of 3.9*10^24 Watts. At what rate it it losing mass due to this radiation? Homework Equations E = Δmc^2 E = mc^2 - m0c^2 Where m0 rep. rest mass. The Attempt at a Solution For this one, I am unsure as to how I would go...
9. ### Neutron must travel so that kinetic energy = rest energy

Honestly, I have to say I overlooked that "-" sign. Thank you Pengwuino.
10. ### Neutron must travel so that kinetic energy = rest energy

Problem statement How fast must a neutron be travelling relative to a detector in order to have a measured kinetic energy that is equal to its rest energy? An "attempt" I know Ek = mc^2 - m0c^2 But if Ek = m0c^2, wouldn't the two terms cancel out from this equation? I am having trouble...
11. ### Simplest Way of finding zeros of cubic eq when rational roots test fails

Uh.. That was the first time I ever heard any of those methods, so could anyone give me a few pointers just to show how I start off with one of the methods above?
12. ### Simplest Way of finding zeros of cubic eq when rational roots test fails

Homework Statement Find the zeros of the cubic equation: y = x^3 -9x^2 + 15x + 30 How do we find the zeros of this? In this case, subbing in x-values that will make it equal 0 does not work.
13. ### Help with understanding Young's Derivation

Homework Statement Here they are deriving the equation for Young's experiment: http://www.physicsclassroom.com/Class/light/U12L3c.cfm The part where they start bringing up "Assertion" and "Logic/Rationale" is where I got confused: They mention for part ii) that if the distance L >>> y, then...
14. ### Sketch this curve (two multipled root functions)

Homework Statement Sketch the curve defined by g(x) = x^{1/3}*(x+3)^{2/3} Homework Equations First Derivative Second Derivative The Attempt at a Solution I attempted to use the algorithm for curve sketching: 1) Find the intercepts 2) First Derivative; look for extrema and points where f'(x)...
15. ### What force would be this replaced charge experience?

Homework Statement A charge q1 = +4.0nC experiences a force of 3*10^-5N to the east when placed in an electric field. If the charged is replaced by another, q2 = -12nC, what will be the magnitude and direction of the force on the charge at that position? Homework Equations Coulomb's Law...

Homework Statement A parent takes their child to a water slide which is shaped similar to a portion of a parabola (see diagram). There is an elevator 3m from the edge of the pool. The elevator takes the rider to the top of the slide which is 19m above ground. The rider slides down and falls...
17. ### Kid going down slide

Wait one minute. I am posting something.
18. ### Find the minimum distance from a curve to a point not on it

Would you explain what you mean?
19. ### Kid going down slide

If given only the coordinates of the centre of a circle, how would we solve for the "r" value in the circle equation? Also, how does this make sense? I don't understand why we would use a circle to get the minimum distance.
20. ### Find the minimum distance from a curve to a point not on it

Homework Statement You are given point (1,2). f(x) = 0.199445983x^2 - 3.789473684x + 19 f'(x) = 0.398891966x - 3.789473684 You also know (0,19), (9.5,1) <-- this is the vertex. This graph has the domain 0≤ x ≤ 9.5 Find the point on the curve that when joined to a line segment with...
21. ### Kid going down slide

Here is extra work done: Ok here is the quadratic equation without any rounding done: 0.199445983x^2 - 3.789473684x + 19 = f(x) f(9.5) = 0.999999968 ≈ 1 I know that the following points would be on the parabola, had it been complete; "x"-values expressed throughout the entire cartesian domain...
22. ### Kid going down slide

Oh I thought I uploaded it already. It is up there now.
23. ### Kid going down slide

Homework Statement A parent takes their child to a water slide which is shaped similar to a portion of a parabola (see diagram). There is an elevator 3m from the edge of the pool. The elevator takes the rider to the top of the slide which is 19m above ground. The rider slides down and falls...
24. ### Total Electric Potential, when is it zero?

Homework Statement A charge of +6.0µC at point A is seperated 10.0 cm from a charge of -2.0µC at point B. At what locations on the line that passes through the two charges will the total electric potential be 0? The Attempt at a Solution [(+) A] ------------------------------ [(-) B] I...
25. ### Find the electric field intensity at point D

[b]1. The problem statement, all variables and given/knownThe diagram shows three small charges at three corners of a rectangle; charge A is -12µC, charge B is -15µC and charge C is +8.1µC. Calculate the magnitude and direction of the electric field intensity at the fourth corner, D. The...

Would you mind giving me any real-life examples that explain this concept?
27. ### Need help understanding this concept on field intensity

Homework Statement We are looking at gravitational field intensity in particular here, and using the earth as an example. The question states: Calculate the gravitational field intensity at a height of 300.0 km from Earth's surface. Why is it that: Since the point in question is outside of...
28. ### Collection of Charges

So if the Fx forces did not cancel each other out, then the net force would be 3 times as great?
29. ### Collection of Charges

Alright this is what I know about vectors: > Dot/Cross Product > Splitting a vector into its x/y components > Scalar/Vector projections So yes, I do have a good base when it comes with vectors.
30. ### Collection of Charges

Yes, please if you can. I understand what you mean by them not cancelling out completely, thank you for your help on that.