The easiest way I know to explain it is this:
-- Take a flashlight and a ball into a dark room.
-- Turn on the flashlight and point it at the ball.
-- Half of the ball is lighted up by the flashlight, and the other half is dark.
-- There is no way you can turn or twist the ball to make more or less
than 50% of it lighted up and more or less than 50% of it dark.
<em>Everything</em> in the solar system ... as long as it's shaped like a ball ... is
half illuminated by the sun and half dark.
Answer:
A _commutator_ is used in a motor to switch the direction of the magnetic field created by the current.
The rotating part of a motor that holds the electromagnets is called the __armature___.
Electric current passes through the _brushes_ and into the electromagnets in an electric motor.
A motor turns _electrical_ energy into _mechanical_ energy.
Explanation:
A commutator, which is a split ring rotary switching device, reverses the direction of the current between the external circuit and the rotor. Reversing the current reverses the magnetic field.
The armature comprises the rotating part of the motor and the electromagnets
A brush is the electrical contact for conducting current through the moving and stationary parts of an electric motor
An electric motor turns electrical energy into mechanical energy.
Answer:
s = 1.7 m
Explanation:
from the question we are given the following:
Mass of package (m) = 5 kg
mass of the asteriod (M) = 7.6 x 10^{20} kg
radius = 8 x 10^5 m
velocity of package (v) = 170 m/s
spring constant (k) = 2.8 N/m
compression (s) = ?
Assuming that no non conservative force is acting on the system here, the initial and final energies of the system will be the same. Therefore
• Ei = Ef
• Ei = energy in the spring + gravitational potential energy of the system
• Ei = \frac{1}{2}ks^{2} + \frac{GMm}{r}
• Ef = kinetic energy of the object
• Ef = \frac{1}{2}mv^{2}
• \frac{1}{2}ks^{2} + (-\frac{GMm}{r}) = \frac{1}{2}mv^{2}
• s = 
s = 
s = 1.7 m
The formula for kinetic energy = ½m·v<span>2
1/2 * 55 kg x 5,87 m/s ^2 = 27.5 x </span>34.4569 = <span>947.56475 Joule </span>≈ 948 J
<span>Each of these systems has exactly one degree of freedom and hence only one natural frequency obtained by solving the differential equation describing the respective motions. For the case of the simple pendulum of length L the governing differential equation is d^2x/dt^2 = - gx/L with the natural frequency f = 1/(2π) √(g/L). For the mass-spring system the governing differential equation is m d^2x/dt^2 = - kx (k is the spring constant) with the natural frequency ω = √(k/m). Note that the normal modes are also called resonant modes; the Wikipedia article below solves the problem for a system of two masses and two springs to obtain two normal modes of oscillation.</span>
