As you stand near a railroad track, a train passes by at a speed of 30.5 m/s while sounding its horn at a frequency of 217 hz. what frequency do you hear as the train approaches you and what frequency while it recedes? take the speed of sound in air to be 343 m/s.

Acar of mass m goes around a banked curve of radius r with speed v. if the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to 101) a) mv2/r b) mg/2. d) mg e) tan[v2/(eg)]

Which of the following are considered noble gases? a. bromine b. neon c. argon d. chlorine

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?