Askier is pulled by a tow rope up a frictionless ski slope that makes an angle of 7.6° with the horizontal. the rope moves parallel to the slope with a constant speed of 1.2 m/s. the force of the rope does 960 j of work on the skier as the skier moves a distance of 7.9 m up the incline. (a) if the rope moved with a constant speed of 2.7 m/s, how much work would the force of the rope do on the skier as the skier moved a distance of 7.9 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 1.2 m/s and (c) 2.7 m/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 ⇒

Why does lightning travel from clouds to the ground?

Select the correct answer. what does the process of natural selection involve?