Recent content by deezy

Homework Statement Three charges with magnitude 8 × 10^{-4} C are located at (1, 0), (0 , 0), and (-1, 0) meters. The middle charge is negative, and the other two positive. What is the net Coulombic force exerted by them on a negative 8 × 10^{-5} C charge at (0, 2)? k = 9.0 × 10^9 N∙m^2/C^2...

Never mind, I figured out what I was doing wrong. First you consider the initial and final momentum... p_i = p_f m_A v_i = (m_A + m_B)v_f Solve for v_f... Then \frac {1}{2} kA^2 = \frac {1}{2} (m_A + m_B) v^2.

Homework Statement Block “A” is released with initial velocity v=10 m/s. Find the period and the amplitude of oscillations after inelastic collision of block “A” with block “B”. The mass of block “A” is 2 kg, the mass of block “B” is 2 kg. The spring constants of the springs are 100 N/m and 300...

I was using KE as the kinetic energy of the spring... wasn't sure if energy in a spring should be referred to as kinetic energy or just energy. Should it just be E for energy?

This may be it, I think: K = \frac{1}{6} U U = \frac{1}{2} kx^2 KE = U + K = U + \frac{1}{6} U = \frac{7}{6} U = \frac {7}{6} \frac {1}{2} kx^2 KE = \frac {1}{2} kA^2 \frac{1}{2} kA^2 = \frac {7}{6} \frac {1}{2} kx^2 A^2 = \frac{7}{6}x^2 (0.1)^2 = \frac {7}{6}x^2 x \approx 0.0926 m

Homework Statement The amplitude of simple harmonic oscillation is A = 10 cm. Find a displacement x when K = 1/6 U. Here K is a kinetic energy and U is a potential energy. Homework Equations KE = \frac{1}{2} k A^2 U = \frac{1}{2} k x^2 The Attempt at a Solution I'm not sure the...

Homework Statement What is the moment of inertia of an 8 kg, 40 cm diameter disk for rotation through the edge of the disk? Homework Equations I = \frac{1}{2}MR^2 The Attempt at a Solution Inertia at the center of the disk would be I = \frac{1}{2}MR^2, right? I'm not sure what...

Ah... so W_{friction} = KE_{spring} = \frac{1}{2}k \Delta x^2 = \frac{1}{2} \cdot 200 \cdot .2^2?

Homework Statement A horizontal spring with spring constant 200 N/m is compressed 20 cm and used to launch a box across a rough horizontal surface. After traveling a distance it stops. What is the work done by friction force? Homework Equations W = F \cdot d KE_{spring} = \frac{1}{2}k \Delta...

So I use F = \frac {mv^2}{r} to solve for velocity, and use v = \omega r to solve for the angular velocity?

Oops, v is supposed to be 7.38 m/s. I used the sine function because that was part of the angular velocity formula. But keep in mind that I wasn't sure if I was using the right formulas.

Ah yes I forgot the radius was different from the length of the rope. r = 1 * cos 10 = .98m 22.23 = .4 * \frac {v^2}{.98} v = 7.38 m/s \omega = \frac {7.38 sin 10} {.98} \omega = 1.32/sec So at this point, is the answer in radians/sec? If not, at which point do I convert it?

Homework Statement A student ties a 400g rock to a 1.0m long string and swings it around her head in a horizontal circle. What angular speed does the string tilt down at a 10° angle? m = 400g = .4kg r = 1m Homework Equations F = \frac {mv^2}{r} \omega = \frac {|v|sin \theta}{|r|}...

Homework Statement Forces of 10 N north and 20 N east are simultaneously applied to a 10-kg object as it rests on a frictionless horizontal table. What is the magnitude of the object's acceleration? Homework Equations a = \frac {F_{net}}{m} The Attempt at a Solution a_{north} = \frac...

How do I separate the forces into x, y components?