. If a siren produces a 300 Hz. frequency and is moving away from the listener with a speed of 45 m/s relative to the air and the listener is moving towards the siren with a speed of 15 m/s relative to the air, the frequency the listener hears is most near:

Transfer chemicals from one location to another to weather objects. a-water b-physical weathering c-chemical weathering

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?