<span>A measurement
that both magnitude and direction is a vector quantity. An example of this is a
moving car. The car exerts force due to its thrust and weight that runs in it. This
will give us the magnitude of the car. The resulting motion of the car in terms
of displacement, velocity and acceleration that determines its direction makes
it a vector quantity. On the other hand, a measurement that has only magnitude is
a scalar quantity. The energy exerted by the engine of the car is a scalar
quantity.</span>
Answer:
<em>No, a rigid body cannot experience any acceleration when the resultant force acting on the body is zero.</em>
Explanation:
If the net force on a body is zero, then it means that all the forces acting on the body are balanced and cancel out one another. This sate of equilibrium can be static equilibrium (like that of a rigid body), or dynamic equilibrium (that of a car moving with constant velocity)
For a body under this type of equilibrium,
ΣF = 0 ...1
where ΣF is the resultant force (total effective force due to all the forces acting on the body)
For a body to accelerate, there must be a force acting on it. The acceleration of a body is proportional to the force applied, for a constant mass of the body. The relationship between the net force and mass is given as
ΣF = ma ...2
where m is the mass of the body
a is the acceleration of the body
Substituting equation 2 into equation 1, we have
0 = ma
therefore,
a = 0
this means that<em> if the resultant force acting on a rigid body is zero, then there won't be any force available to produce acceleration on the body.</em>
<em></em>
The average dissipated power in a resistor in a ac circuit is:
where R is the resistance, and
is the root mean square current, defined as
where
is the peak value of the current. Substituting the second formula into the first one, we find
and if we re-arrange this formula and use the data of the problem, we can find the value of the peak current I0: