Natural selection explains how populations change as their environment change. How does variation affect natural selection?

Ajogger accelerates from rest to 4.86 m/s in 2.43 s. a car accelerates from 20.6 to 32.7 m/s also in 2.43 s. (a) find the magnitude of the acceleration of the jogger. (b) determine the magnitude of the acceleration of the car. (c) how much further does the car travel than the jogger during the 2.43 s?

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 ⇒

In a good thermo flask the main cause of heat loss is