A white light is, by definition, apparently colorless light, for example ordinary daylight. It contains all the wavelengths of the visible spectrum at equal intensity.
so A.
Answer:
18min
Explanation:
v=d/t
t=d/v= 27/90 =0.3hrs =18min
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
.