Answer:
Explanation:
<u>Uniform Acceleration </u>
When an object changes its velocity at the same rate, the acceleration is constant.
The relation between the initial and final speeds is:
Where:
vf = Final speed
vo = Initial speed
a = Constant acceleration
t = Elapsed time
It's known a train moves from rest (vo=0) to a speed of vf=25 m/s in t=30 seconds. It's required to calculate the acceleration.
Solving for a:
Substituting:
Answer:
The relationship between the initial stored energy and the stored energy after the dielectric is inserted
is:
c)
Explanation:
A parallel plate capacitor with that is connected to a voltage source
holds a charge of
. Then we disconnect the voltage source and keep the charge
constant . If we insert a dielectric of
between the plates while we keep the charge constant, we found that the potential decreases as:
The capacitance is modified as:
The stored energy without the dielectric is
The stored energy after the dielectric is inserted is:
If we replace in the above equation the values of V and C we get that
Finally