1. when a motor is turned on, electrical energy is transformed to mechanical energy plus heat energy.
true or false

2. the outward evidence for this transformation can be seen only in the mechanical motion of the motor.
true or false

3. what is true of the efficiency of this motor?
a. it is more than 100% efficient
b. it is 100% efficient
c. it is less than 100% efficient
d. none of the above

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?

Awalk up the phase change graph worksheet

The frequency of vibrations of a vibrating violin string is given by f = 1 2l t ρ where l is the length of the string, t is its tension, and ρ is its linear density.† (a) find the rate of change of the frequency with respect to the following. (i) the length (when t and ρ are constant) (ii) the tension (when l and ρ are constant) (iii) the linear density (when l and t are constant) (b) the pitch of a note (how high or low the note sounds) is determined by the frequency f. (the higher the frequency, the higher the pitch.) use the signs of the derivatives in part (a) to determine what happens to the pitch of a note for the following. (i) when the effective length of a string is decreased by placing a finger on the string so a shorter portion of the string vibrates df dl 0 and l is ⇒ f is ⇒ (ii) when the tension is increased by turning a tuning peg df dt 0 and t is ⇒ f is ⇒ (iii) when the linear density is increased by switching to another string df dρ 0 and ρ is ⇒ f is ⇒