Answer:
Commutator is a ring which reverse the direction of current in AC circuit so that the coil connected to it will continuous to move in the same direction.
Explanation:
In motors there exist a coil which is rotated due to torque of magnetic field when current flow through it. Since AC current is used to run the motor so we know that AC current changes its direction after half cycle.
So here commutator plays an important role to reverse the direction of current after every half cycle so that the current goes in same direction always into the coil.
This will produce a constant direction torque on the coil so that it will rotate in same sense always.
So commutator role is to provide same direction current to the coil by reversing its direction after every half cycle
Answer:
Solution given:
height [H]=25m
initial velocity [u]=8.25m/s
g=9.8m/s
now;
a. How long is the ball in flight before striking the ground?
Time of flight =?
Now
Time of flight=
substituting value
- =
- =2.26seconds
<h3>
<u>the ball is in flight before striking the ground for 2.26seconds</u>.</h3>
b. How far from the building does the ball strike the ground?
<u>H</u><u>o</u><u>r</u><u>i</u><u>z</u><u>o</u><u>n</u><u>t</u><u>a</u><u>l</u><u> </u>range=?
we have
Horizontal range=u*
<h3>
<u>The ball strikes 18.63m far from building</u>. </h3>
By definition, acceleration is the change in velocity per change of time. As time passes by, the time increases in value. So, when the acceleration is decreasing while the time is increasing, then that means that the change of velocity is also decreasing with time. So, optimally, the initial velocity and the velocity at any time are very relatively close to each other,
