The sentence can be completed as follows:
The wavelength of an electromagnetic waves is the spatial distance between two successive troughs.
Note that the wavelength of a wave can also measured as the spatial distance between two successive crests of the wave. Also note that the second part of the sentence ("also known as the period") is not true, because period is another thing (in fact, the period is the time interval between two successive troughs).
Answer:



Explanation:
= Torque = 36.5 Nm
= Initial angular velocity = 0
= Final angular velocity = 10.3 rad/s
t = Time = 6.1 s
I = Moment of inertia
From the kinematic equations of linear motion we have

Torque is given by

The wheel's moment of inertia is 
t = 60.6 s
= 10.3 rad/s
= 0

Frictional torque is given by

The magnitude of the torque caused by friction is 
Speeding up

Slowing down

Total number of revolutions


The total number of revolutions the wheel goes through is
.
There all diffrent speeds