7. In which of the following situations is the Doppler effect absent? -Neither the source nor the observer is moving relative to one another.
-The source is moving away from the observer
-The observer is moving toward the source.
-The source and the observer are moving towards each other.

What are atoms of the same element with varying number of neutrons

Wind and moving water provide energy. question 1 options: chemical mechanical thermal none of the above

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)