A car sounds its horn while approaching an observer at 20 m/s. If the observer hears a frequency of 430 Hz, find the frequency emitted by the car's horn. Assume the speed of sound is 343 m/s.

Suppose you plot the distance traveled by an object at various times and you discover that the graph is not a straight line. what does this indicate about the object's acceleration?

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)

Atypical jetliner lands at a speed of 146 mi/h and decelerates at the rate of (10.4 mi/h)/s. if the jetliner travels at a constant speed of 146 mi/h for 1.5 s after landing before applying the brakes, what is the total displacement of the jetliner between touchdown on the runway and coming to rest?