# Search results

1. ### Loop-the-loop with potentional and kinetic energy

Centripetal acceleration must be greater than gravitational acceleration.

KE \gt PE
3. ### Loop-the-loop with potentional and kinetic energy

Hmm... if it had zero velocity at the top, it would stop and fall straight down. I need to develop a different approach. Perhaps at the top
4. ### Loop-the-loop with potentional and kinetic energy

It needs enough kinetic energy to reach the top, which gets turned into potential energy right when it gets there. That way, it will make it around the loop.
5. ### Loop-the-loop with potentional and kinetic energy

Homework Statement A mass m = 77 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius R = 15.1 m and finally a flat straight section at the same height as the center of the loop (15.1 m off the ground). Since the mass would not make it around the loop if...
6. ### Pendulum Velocity

The initial energy will all be potential (PE = mgh) and the final energy will be entirely kintic (KE = 1/2 mv^2)
7. ### Pendulum Velocity

Homework Statement A mass m = 5.5 kg hangs on the end of a massless rope L = 1.81 m long. The pendulum is held horizontal and released from rest. How fast is the mass moving at the bottom of its path? Homework Equations a_c = \frac {v^2}{r} F = ma v = v_o + at The Attempt at a Solution I...
8. ### Spring launched box sliding over friction surface

Homework Statement A block with mass m = 14 kg rests on a frictionless table and is accelerated by a spring with spring constant k = 4085 N/m after being compressed a distance x_1 = 0.546 m from the spring’s unstretched length. The floor is frictionless except for a rough patch a distance d =...
9. ### Work by tension on masses

Thank-you so much guys! I got it figured out.
10. ### Work by tension on masses

So then into W=Fd W=\cfrac{m_1m_2gd}{m_1 + m_2}
11. ### Work by tension on masses

I worked it like this: tension will equal the sum of both forces, so m_2a + m_2g = T and T = m_1a solve for a a = \cfrac{m_2g}{m_1 + m_2} plug in T = \cfrac{m_1m_2g}{m_1+m_2}
12. ### Work by tension on masses

And the 2nd law equations for tension are F_1=m_1a F_2=m_2g right?
13. ### Work by tension on masses

yes, it was a typo
14. ### Work by tension on masses

So, solving for tension, I get T = \cfrac{m_1m_2g}{m_1-m_2} and then putting it into W=Fd I get W=\cfrac{m_2m_2gd}{m_1+m_2} Is this correct?
15. ### Work by tension on masses

Would tension then be T=m_1g or would it involve both mass 1 and mass 2?
16. ### Work by tension on masses

After doing that, I get this. F=ma so T=m_2g to get a, I solve F=ma to get a=F/m (and m is m_1 + m_2), and then plugin into W = Fd I get W=mad so W= \frac{(m_2)(T)(d)}{m_1 + m_2} and plugging in I get W=10.3177 which is wrong. I think I'm even closer, but there is an error somewhere, maybe...
17. ### Work by tension on masses

Homework Statement A mass m_1 = 4.1 kg rests on a frictionless table and connected by a massless pulley to another mass m_2 = 3 kg, which hangs freely from the string. When released, the hanging mass falls a distance d=0.83m. How much work is done by tension on m_1? Homework Equations v^2 =...
18. ### Engineering Engineering with math major

I am majoring in applied math and considering a minor in physics. Would it be reasonably possible for me to get a job in engineering (electrical or mechanical) with only that background?
19. ### Find parametric equations for the tangent line

I made a mistake. I meant to say tangent vector.
20. ### Find parametric equations for the tangent line

Homework Statement Find parametric equations for the tangent line to the curve with the given parametric equations at the specified point. Homework Equations x = 1+2 \sqrt{t}, \quad y = t^3 - t, \quad z = t^3 + t, \quad (3, 0, 2) The Attempt at a Solution I began by...
21. ### Vector function intersection

Awesome! Thank-you.
22. ### Self-taught physics

(I would like to apologize if this is in the wrong forum; I wasn't sure where to put it) Anyway, I am very interested in studying physics, but my degree (CS) only requires one basic class in classical mechanics. I could take more physics courses to fill science electives, but the physics...
23. ### Vector function intersection

Homework Statement "Find a vector function that represents the curve of intersection of the two surfaces." Homework Equations Cone: z = \sqrt{x^2 + y^2} Plane: z = 1+y The Attempt at a Solution I began by setting x=cos t, so that y = sin t and z = 1+sin t. At this point...
24. ### Relative velocity of plane with vectors

Homework Statement The problem is worded thus: You are on an airplane traveling 30° south of due west at 130 m/s with respect to the air. The air is moving with a speed 30 m/s with respect to the ground due north. (a) What is the speed of the plane with respect to the...
25. ### What time are two thrown balls at the same height?

Would it be t + 0.6 ?
26. ### What time are two thrown balls at the same height?

Homework Statement A red ball is thrown down with an initial speed of 1.2 m/s from a height of 25 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 23.8 m/s, from a height of 0.8 meters above the ground. The force...
27. ### Integration by parts with e and sine

Homework Statement Evaluate the integral. Homework Equations \int e^{2x} sin(3x) dx The Attempt at a Solution I began by using integration by parts. u = sin(3x) v = \frac {e^{2x}} {2} du = 3 cos(3x) dv = e^{2x} dx but I get stuck after that because the...
28. ### Problem with trig integral

Homework Statement Evaluate the integral. Homework Equations \int sin^2(\pi x) cos^5 (\pi x) dx The Attempt at a Solution I tried first by splitting the cosine up \int sin^2(x) [1-cos^2(x)] cos^2(x) cos(x) dx and from there use u-substitution. However, I am not sure what...
29. ### Problem with series

Homework Statement Determine whether the series is convergent or divergent. If it is convergent, find its sum. Homework Equations \sum_{n=1}^{\infty} \frac{1 + 2^n}{3^n} The Attempt at a Solution Hello, I have tried to find the sum of this series using both the...
30. ### Planetary Composition

Oh, and once again, this may be more appropriate for the math forums, but how do I find ρ?