Given that,
Electrical energy of the motor = 2280 J
Kinetic energy = 1606 J
Wasted energy in thermal and sound energy = 550 J
To find,
The efficiency of the motor in percent.
Solution,
Efficiency is defined as the ratio of useful output energy to the total energy.
Total energy = 2280 J
Useful energy = 1606 J
So, the efficiency of the motor is 70.43%.
To solve this problem we need to use the induced voltage ratio law with respect to the number of turns in a solenoid. So
For the given values we have to
Replacing we have that,
Therefore the RMS value for secondary is 30V.
The current can be calculated at the same way, but here are inversely proportional then,
Replacing we have
Therefore the rms value of current for secondary is 40mA
Answer:
what is your question because I seem to not see a question in this question....
1) In an uniformly accelerated motion, the acceleration is given by:
where
is the final speed,
is the initial speed, and
is the time interval between the initial and final point of the motion.
Using the data of the problem:
,
, and the time
, the acceleration is
where the negative sign means that the hockey puck is decelerating.
2) The frictional force F between the puck and ice is responsible for the deceleration of the puck, and for second Newton's law this force is equal to the product between the mass of the puck m and the acceleration:
(1)
The frictional force can also be written as
(2)
where
is the coefficient of kinetic friction, and where the negative sign is due to the fact that the frictional force acts against the direction of motion of the puck. By equilizing (1) and (2) we can find the value of this coefficient: