Radar guns are used to measure the speed of moving objects. Radar guns work by projecting radio waves of known frequencies onto moving objects.

How is a radar gun able to calculate the speed of a moving object using radio waves?

A.

Radio waves are reflected off of the moving object, which causes a change in frequency that can be analyzed by the software of the radar gun to calculate the object's speed.

B.

Radio waves are diffracted by the moving object, which causes a change in wave speed that can be analyzed by the software of the radar gun to calculate the object's speed.

C.

Radio waves are refracted by the moving object, and the angle of refraction of the waves can be analyzed by the software of the radar gun to calculate the object's speed.

D.

Radio waves are absorbed by the moving object, which causes an increase in the temperature of the object that can be analyzed by the software of the radar gun to calculate the object's speed

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

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 are atoms of the same element with varying number of neutrons