What conclusion does the student most likely make based
on this data?

Light waves always travel the same speed; however, the
speed of sound is determined by the medium that it
travels through
O All sound waves always have the same energy, so the
temperature of the medium does not affect wave speed.
O Light needs to vibrate particles, so it travels fastest in
tightly packed solids, while sound does not need a
medium, so it travels fastest in a gas.
Tightly packed particles in solids slow down the light
waves, however, sound waves make particles bounce
into each other, so they travel faster in solids.
Which one?

For problems 1-3, consider a simple dc brush motor with a permanent magnet stator. with an an consider a simple dc brush motor with a permanent magnet ae supply voltage of 100 v, the no-load speed of the motor is 1000 rpm. this motor can provide a torque of 1.9 n-m at 800 rpm drawing a current of 2 a current are both zero at no load.) 1. with an armature supply voltage of 100 v, the motor is operated at 900 rpm. what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input? what is the energy efficiency of the motor? with an armature supply voltage of 100 v, the motor is operated at 1100 rpm (where it acts as a generator). what torque input is required? what mechanical power is required what current is generated? what is the electrical power generated? what is the energy efficiency of the motor acting as a generator? 2. with an armature supply voltage raised to 120 v, the motor is operated at 1000 rpm. what is the no-load speed? what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input what is the energy efficiency of the motor? 3.

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b.refraction c.diffraction d. interference

What is the measurement of how fast an object moves relative to a reference point?