Two idenical speakers driven by the same signal produce 680 Hz soundwaves.  The speakers are different distances away from you.  What must be the difference in distances to result in destructive interference?

(1) 0.85 m

(2) 1.3 m

(3) .30 m

(4) .25 m

An engineer in a moving train blows the train's horn while the train is moving away from a woman standing on a nearby platform. Compared to the frequency of the sound that the engineer hears, the lady standing on the platform hears a sound with:

(1) the same wavelength

(2) more variation in tone

(3) greater amplitude

(4) a lower frequency

A college soccer star runs towards the opposing goal and kicks a 0.5 kg stationary inflated ball with a total force of 50 newtons.  What is the force on the athlete's foot?

(1) 0 N

(2) 25 N

(3) 50 N

(4) 100 N

A 3 microfarad capacitor is connected with a 6 microfarad capacitor. When a 300 volt potential difference is applied across this combination, the total energy stored in the two capacitors is:

(1) 0.41 J

(2) 0.27 J

(3) 0.09 J

(4) 0.81 J

(5) 0.18 J

A net force of 10 newtons accelerates an object at 5.0 meters per second². What net force would be required to accelerate the same object at 1.0 meter per second²?

(1) 1N
(2) 2N
(3) 5N
(4) 50N