A police car is approaching at a speed of 20.0 m/s with its siren emitting a frequency of 1.0 kHz. What frequency does a stationary observer detect? The speed of sound in this case is 330 m/s.

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?

Which describes an object in projectile motion? check all that apply. a.gravity acts to pull the object downb. the object moves in a straight path. c.the forward velocity of the object is 0 m/s. d.the object’s inertia carries it forward. e.the path of the object is curved.

Cyclotrons are widely used in nuclear medicine for producing short-lived radioactive isotopes. these cyclotrons typically accelerate h- (the hydride ion, which has one proton and two electrons) to an energy of 5 mev to 20 mev. this ion has a mass very close to that of a proton because the electron mass is negligible—about 1 2000 of the proton’s mass. a typical magnetic field in such cyclotrons is 1.9 t. (a) what is the speed of a 5.0-mev h-? (b) if the h- has energy 5.0 mev and b = 1.9 t, what is the radius of this ion’s circular orbit?