the distance L between charges q = + / - 2 nC is equal to 20 cm. determine the intensity of the field created by these charges at a point located at a distance of r = 15cm from the first charge and r = 10cm from the second charge

Shelly experiences a backward jolt when the driver starts the school bus. which of the following explains this phenomenon? a. the inertia of shelly b. the inertia of the bus c. the normal force of the seats on shelly d. the net force acting on shelly in a backward direction e. a zero net force acting on shelly

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 an example of motion in two dimensions?