You are driving at the speed of 27.7 m/s (61.9764 mph) when suddenly the car in front of you (previously traveling at the same speed) brakes and begins to slow down with the largest deceleration possible without skid- ding. considering an average human reaction, you press your brakes 0.507 s later. you also brake and decelerate as rapidly as possible without skidding. assume that the coefficient of static friction is 0.868 between both cars’ wheels and the road. the acceleration of gravity is 9.8 m/s2 . calculate the acceleration of the car in front of you when it brakes. answer in units of m/s2.

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 ⇒

Sound is a disturbance that travels through a medium as a

The photo shows sugar dissolved into a solution with excess sugar at the bottom of the jar this type of solution is classified as a. unsaturated b. compound c. saturated d. plasma