Answer:
12.3 m/s
Explanation:
The Doppler equation describes how sound frequency depends on relative velocities:
fr = fs (c + vr)/(c + vs),
where fr is the frequency heard by the receiver,
fs is the frequency emitted at the source,
c is the speed of sound,
vr is the velocity of the receiver,
and vs is the velocity of the source.
Note: vr is positive if the receiver is moving towards the source, negative if away.
Conversely, vs is positive if the receiver is moving away from the source, and negative if towards.
Given:
fs = 894 Hz
fr = 926 Hz
c = 343 m/s
vs = 0 m/s
Find: vr
926 = 894 (343 + vr) / (343 + 0)
vr = 12.3
The speed of the car is 12.3 m/s.
 
        
             
        
        
        
Answer:
0.3 %
Explanation:
Earth cleans and replenishes the water supply through the hydrologic cycle. The earth has an abundance of water, but unfortunately, only a small percentage, is even usable by people.
 
        
             
        
        
        
Answer:
A
Explanation:
Kinetic energy must be moving. Potential energy has the ability to move but is not doing so at the moment.
A is likely the answer. But there's lots involved in that kind of motion.
B If the ball is elevated, it implies it is not moving yet. It has potential energy.
C Again, the spring is compressed. It will push something when it moves, but it is not moving yet.
D The load gun's bullet is not moving. It's still potential energy.
E. The mouse trap is set, but it is not moving. When the mouse eats the bait then it's potential energy will transform into kinetic energy.