1. Let the distance from end 1 at which the 800N person will not cause the plank to tip about the support A be x.

The plank will experience normal reaction of the supports as shown in the fig.. In general, NA + NB = 100+800 = 900 N. However, when the plank is on the verge of tipping about the support A, NB will become zero.

For equilibrium, net moment of all forces about support A must be zero. Hence, taking counter clockwise as +ve and clockwise -ve, we have :

800(1-x) - 100x4 = 0 or x = 0.5m

2. Force F can be resolved into components Fx = F cos20 = 0.94F and Fy = F sin20 = 0.34F

For equilibrium, net moment of forces about the hinge must be zero. Hence,

145x(3.13/2) - Fy (2.5) = 0 [Fx has no moment about the hinge as it passes through the hinge]

(A) A damped oscillator is described by the equation:
m [(x)ddot] = ?b [(x)dot] ? kx
What is the condition for critical damping? Assume this condition is satisfied.
(B) For t < 0 the mass is at rest at x = 0. The mass is set in motion by a sharp impulsive force at t = 0, so that the velocity is v0 at time t = 0

Need help with the following physics problems:
1. About medio-lateral axes, the moment of inertia of a person's upper arm (shoulder-elbow segment) was found to be 0.06 kg.m^2 for rotation about the shoulder joint, and 0.08 kg.m^2 for rotation about the elbow joint. Why are these numbers different?
2. A diver's body, whil

Please help with the following problems.
(1) Suppose that a photon has energy of 5 x 10 -19 J. (five times ten to the negative 19th Joule) What's the wavelength of this photon? What is its frequency?
(2) The photon in the above problem strikes a metal plate that has a work function of PHI = 3 x 10 ^ -19 J. What's the max

Please see the attachment for the formatted problem.
3. Consider again the lattice of N spin-1/2 particles in an external homogeneous magnetic field, where each particle has two possible states: spin "down" with energy e = 0 and spin "up" with energy e = 1/2". The microstate of the system is specified by the energy states of

An open channel having a rectangular cross section is laid so that the rate of grade is 0.00048. The width of the channel is 10.00 ft, and the value of n in Kutter's formula may be taken as 0.011. When the depth of the water in the channel is 4.00 ft, the velocity computed by the Chezy formula is?

In an industrial cooling process, water is circulated through a system. If the water is pumped with a speed of 0.45 m/s under a pressure of 400 torr from the first floor through a 6.0-cm diameter pipe, what will be the pressure on the next floor 4.0 m above in a pipe with a diameter of 2.0 cm?

A 4.0 kg toy race car can move along an x axis. The figure below gives Fx of the force acting on the car, which begins at rest at time t = 0. (The vertical axis is marked in increments of 2 N.)
See the attached document for the necessary graph.
(a) What is the momentum of the car at t = 6.0 s
(b) What is the moment

Which of the following statements are true about quantum theory?
1.(T/F)photoelectric effect shows the particle-like nature of light
2.(T/F) in addition to light, matter may also display wave-like properties
3.(T/F) the energy of a quantum of light is related to its wavelength
4.(T/F) a particle of light is calle

The FlyRight Aircraft Maintenance (FRAM) division of the FlyRight Company (FRC) performs all maintenance for FRC's aircraft. Produce a data model segment that reflects the following business rules:
All mechanics are FRC employees. Not all employees are mechanics. Some mechanics are specialized in engine (EN) maintenance. Some