Frederick has a lawnmower that is fueled by gasoline. His science teacher told him that not all of the energy stored in the gasoline in the lawnmower is converted into the energy of motion that spins the lawnmower blade. Which of the following statements is the most accurate explanation of this situation?
A.
An isolated system always loses energy to its environment.
B.
The law of conservation of energy is not obeyed by isolated systems.
C.
Energy can leave an open system and enter the surroundings.
D.
The total amount of energy never changes in an open system.

Dry ice is solid carbon dioxide that is used in the transport of food and medicine. dry ice becomes a gas at –78.5°c without becoming a liquid first.

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 ⇒

The cerebellum controls? thirst sensations sleep-wake cycles hand-eye coordination heart rate and pulse