You are driving slowly on the highway at 50 mph when a police car with its lights flashing passes you going 100 mph. relative to you, the police officer is moving 50 mph. far in the future, when humans have mastered space travel, an astronaut is moving in a spaceship at half the speed of light, v = c/2, relative to earth, when a light beam sent from earth moving parallel to the spaceship passes it moving at v = c. the astronaut measures the light beam to be moving ata. v=2c b. v=c/2 c. v=c d. v=3c/2

Can anybody me with this? ? (picture included.)

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 ⇒

What is the temperature in degrees celsius of a substance with a tempature of 49k