To throw a discus, the thrower holds it with a fully out-stretched arm. starting from rest, he begins to turn with a con-stant angular acceleration, releasing the discus after making one complete revolution. the diameter of the circle in which the discus moves is about 1.8 m. if the thrower takes 1.0 s to complete one revolution, starting from rest, what will be the speed of the discus at release?

Describe the path of a ray that approaches a mirror parallel to the principal axis.

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 ⇒

Which of the following is not a physical property of mattera. melting pointb.heat of combustionc. viscosityd. boiling point